View Full Version : Real Navigation Mod
Read the whole thread, lots of info and problems. Check this post for updated links (22.06.2007).
This compilation fixes all (?) the bugs from Kaleun Freddies compilation. It's GWX 1.03 ready, optimized for 1024x768. See readme inside.
realnav.zip 1.01 (http://mrhadrys.com/silenthunter/realnav.zip)
realnava.zip 1.01 (Assisted) (http://mrhadrys.com/silenthunter/realnava.zip)
Check out original thread by K. Freddie containing links to star maps, sunrise/set tables and nav help:
http://www.subsim.com/radioroom/showthread.php?t=113975
http://www.subsim.com/radioroom/showthread.php?t=114812
Clean and simple Wiki explanation of navigation basics:
http://en.wikipedia.org/wiki/Celestial_navigation
Great world map with precise long/lats. Thanks to it now I have a more or less scheme for a specific zoom level of SH3 map. Good start to make precise maps of important areas.
http://encarta.msn.com/encnet/features/mapcenter/map.aspx
My navigation from recent patrol. It was quite good, my error was less then 10km. Couldn't see the stars because of heavy overcast all the time... As we now know, the sea was calm so the boat was on course all the time.
http://mrhadrys.com/silenthunter/realnav.jpg
I've got one little question for this mod too:
Sailing around by real navigation methods sounds fine but how do you gonna make your contact plottings when engaging something ?
Marking a ship's position on the map is always relative to your own position, how would you get a relatively precise drawing if you don't know even your own position that precisely ? And without exact contact markings you cannot estimate it's course and speed.
The only thing I could image to get around this is to make a full stop, estimate some fix point as close to your real position as possible and do your observings only from that point.
Or aren't 'Real Navigation' attacking anything ?
gb, i.
@Hadrys: Nice drawings btw ;)
Marking a ship's position on the map is always relative to your own position, how would you get a relatively precise drawing if you don't know even your own position that precisely ? And without exact contact markings you cannot estimate it's course and speed.
The only thing I could image to get around this is to make a full stop, estimate some fix point as close to your real position as possible and do your observings only from that point.
This is the real deal! As you just wrote it has to be relative (and was!?). I had only a chance to attack 3 ships and try to figure out some escorts during that patrol and it wasn't a big problem. If you have a brief chance of visual contact that's easy from than.
I suppose there are two methods. You can plot from your current position but that would mess things up. More reasonable I think, is to mark your last position, time and course than just start plotting your target on a clear piece of map, co you could include small course adjustments. Than after attack you could peacefully recreate your position, back on course and proceed with normal navigation. Making notes is crucial. In general I suppose it looks very scary but after just one short patrol my perception of space, directions, bearings etc is way better. It becomes natural! Don't count on sinking every ship but now it's as hard as it should be and the satisfaction is enormous!
To be honest, we should have some help, that's what our crew's for right...? but I have no idea how it could be simulated accordingly, their mistakes, their consultations with Her Kaleun etc.
joegrundman
06-16-07, 05:02 AM
Marking a ship's position on the map is always relative to your own position, how would you get a relatively precise drawing if you don't know even your own position that precisely ? And without exact contact markings you cannot estimate it's course and speed.
You said it, it's relative to your own position, not absolute, therefore you do not need to know your own absolute position.
So you draw the contact's position from the postion/course drawings you did for your own sub ? If you make little mistakes there, which would be natural, doesn't that flaw the whole attack solution in the end ? Or am I just don't getting something here ?:roll:
So you draw the contact's position from the postion/course drawings you did for your own sub ? If you make little mistakes there, which would be natural, doesn't that flaw the whole attack solution in the end ? Or am I just don't getting something here ?:roll:
But that's the point! As I've wrote, sometimes it's not good or clear to draw from normal course but if I have very far hydro contacts and don't want to change my course yet I just draw distant lines from my actual course with different length representing the sound level and for example 2 km away from my course line.
It looks like you're overthinking it! Install this mod and see for yourself, it's gonna make you to search many different solutions and approaches which all end up very obvious :know: :arrgh!:
I wanted to test this mod anyway, sounds really interesting. There will be always something to do, no more 2 weeks just waiting for something to happen ;).
When I return from my current patrol, I will make a backup of my savegames (in case I mess everything up by accidently sailing to south africa ;) ) and install it.
Do you need images of real starmaps or is it enough to find e.g. the polar star and then use the sextant readings ?
I wanted to test this mod anyway, sounds really interesting. There will be always something to do, no more 2 weeks just waiting for something to happen ;).
When I return from my current patrol, I will make a backup of my savegames (in case I mess everything up by accidently sailing to south africa ;) ) and install it.
Do you need images of real starmaps or is it enough to find e.g. the polar star and then use the sextant readings ?
This mod has a great potential but also many questions to answer yet... Read on both topics contained in readme file. Today maybe my friend will come, he's a captain of private sailing ships (?) and we gonna try to navigate with stars, books, maps. I haven't changed camera angle as mentioned in those topics, the problem is Freddie made this very chaotic, he doesn't have pure GWX...
Also in one thread we concluded that using ctrl+left click on map may help. It shows your precise position under mouse cursor. I use it only in ports as I have lighthouses and other landmarks to determine my starting point before just hitting high seas. It can also be used if the stars are visible and sunrise/set can be observed or sun and moon at the same time to simulate celestial navigation. But that's not a concern as it's stormy all the time near the British islands...
Draw your course, write it down, it's your best friend. I'm just leaving Wilhelmshaven for my 7th patrol. Currently in realtime as I'm laying in my captains corner reading HMS Ulisses and listening to the latest gramophone tracks. It's better to be coming back than leaving behind this beautiful morning...
I've downloaded the mod some time ago, didn't install it yet. I read the manual about how to use the sextant and navigate with help of the stars. Have to wait 'til next week, when I'm back home again to finally test it.
An ingame free writing notepad function would be very useful. Now I have to take care that I don't lose my notes on my desk until I play SH3 again or else I would be lost somewhere at the Atlantic not knowing where I am ;)
It was one hour before midnight, we were only 18 hours from Wilhelmshaven heading WNW and already struggling stormy waves of North Sea. Thank God it wasn't raining, the wind was enough frustrating but somehow the sky was clear! It was probably our last chance to pick up the Polaris so I've yelled down the tower for Walter to bring his toys with him.
Like a true pro, he stated that we're way off course which was undoubtedly confirmed by main compass... damn you Walter. Not a good way to begin our patrol...
----------
OK the point is I've located the Polaris, sextant shows about 54N degrees. This would more or less match with my tiny knowledge. But how to use it precisely? I have no idea about sunset/rise times and how to use that table. Freddie mentions problem with GMT time east of Greenwich.
But the biggest problem so far is getting of the course! It didn't happened last time and if it was marginal. My errors were rather from not too exact drawing and making turns on time. The wind is 12 m/s coming from 126, sea is heavy, boat fights the waves. What does 126 mean? Is it bearing or wind course? If this is course than it should blow from my starboard as I'm going 294 but boat turns about 10 degrees north to 305 every 30 minutes. Can't help it by setting course in different ways, commanding rudder amidships... maybe I should put 1 degree port to compensate? This is getting interesting. As if I wouldn't use ctrl+click I would finish completely lost in the middle of North Sea :|\\
Another idea, I'll try going into different directions and see what happens than!?
http://mrhadrys.com/silenthunter/realnav1.jpg
As far as I know, the wind direction gices teh direction from where it comes. So if you're haeding 000° and wind direction is told as 90° then you're going to drift in west direction.
Seems like some further tests are needed to get used with the subs behaviour in the different weather conditions ;)
As far as I know, the wind direction gices teh direction from where it comes. So if you're haeding 000° and wind direction is told as 90° then you're going to drift in west direction.
Seems like some further tests are needed to get used with the subs behaviour in the different weather conditions ;)
This would make sense - der Wind kommt aus xxx simply means its heading. Don't know why but going N, E, S for 1 hour gave just 1 degree (how do U put degree symbol?) of course change each time and now it's 15 m/s from 225. Going back for 284 gave 7 deg north after an hour... the Brits defend themselves from heading for Scapa?
No Idea on the manual charting, but degree symbol: ALT+0176
Ok, I've done some homework.
First there was no automated system on u-boats, everything had to be plotted by the Stauerman so probably getting a bit lost off course in bad weather was a normal thing.
I've found a great world map Encarta (http://encarta.msn.com/encnet/features/mapcenter/map.aspx) which has superb quality, lots of names, even depths but most importantly precise longs/lats! After a while comparing places accordingly to SH3 map and prime meridian (blue) I've managed to make a photoshop template with long/lats for a specific SH3 zoom level. Take some time to see if it fits to the rest.
Below is an example of what kind of maps I'm thinking about. Precise maps of important areas with lots of geographical names to keep it more real/fun. You can photoprint them, store them on another PC? (I'm using an old laptop). With manual plotting you have enough time to compare different maps, think where to go and what to do next! Also you can put in your patrol log - "after going 5 hours at 284° we finally saw a tiny "Fair Island" on the horizon, a perfect place for an ambush".
Also my previous observation of Polaris confirms my position quite exactly. It was an hour before 00:00 (by that time there was 0 visibility) but the error should be small. Don't have a clue about longitudes yet... help!
http://mrhadrys.com/silenthunter/map-Orkney.jpg
I've encountered a serious problem. I'll try to contact Val but probably he's stuck at the same point.
I've finally figured it out how to obtain long having lat and sunset time. First of all I've made lat measure at noon and it has 20 minutes accuracy which gives 37km error (measured 53°30N, real 55°50N). Quite good for a total rookie.
3 hrs earlier I've noticed sunset time and here's the big problem. It doesn't fit anyhow using Vans almanac. The reading should be 15 minutes before sunset in Greenwich to give my current position which is about 3°50E (-15/4=3°40E). Sunset reading was way out of scale giving +59' difference so we should be 15°W!!
Till now I've observed that from the prime meridian to my current position SH3 shows 468km but Google Earth shows 250 km what gives exactly my 3°50E (1°E/W at 55°N is 62.8km - there is a simple formula for that...). Also the long and lats are equal distance on SH3 map while there should be a disproportion of 1°E/W * ~1.77 = 1° lat in kilometers (at this 55N point). Also 468/250 and you get nearly 1.77.
With above conclusion I went straight W and than N each time @ 10kt for 6 hrs to make 111.12km=1°N. I've made 114km with the sea dead flat so the error is very acceptable depending on varying speed probably. But the problem is that I've made 1°W and 1°N as looking at the map while I should really make 1°46W...
I suppose it ruins the longitude thing and can't be fixed while the whole gameplay coordinates would mess up...
Any ideas? HELP!?
Either way I'm gonna buy KM Sextant some time and hit the Baltic Sea with my also considered as not completely normal friend. I wonder where we finish without looking at GPS :arrgh!::sunny:
http://mrhadrys.com/silenthunter/map-markirung7.jpg
don1reed
06-17-07, 08:42 PM
Hadrys,
Do you have a mod that puts those crisp LAT LONG lines on SH3 Chart?
-...-
Make sure before you buy that KM sextant that you have a professional optics man check it over. The pro will be able to tell if its been dropped or out of serious alignment.
If its in good shape your accuracy at sea should be within 0.1 m.o.a. if the mfg was CASSENS & PLATH or Freiburger.
edit: btw, if any of you gentlemen have a current or old Nautical Almanac lying about, the SR/SS LAN tables on the righthand pages don't change from year to year and can be used.
Best of Luck,
Hadrys,
Do you have a mod that puts those crisp LAT LONG lines on SH3 Chart?
Make sure before you buy that KM sextant that you have a professional optics man check it over. The pro will be able to tell if its been dropped or out of serious alignment.
Nope cause I don't understand this RAW format... either way it's useless now. I suppose that we should forget about getting proper longitudes.
About KM stuff - I have lot's of time to collect those few desired items, build that 100+ cm VIIc model with brass details, dive deeper, go further etc but thx for the tip! I'll sure do that.
That's a real pity. I was so looking forward to finally test this mod on my own. I will do it anyways and see where I get with it ;)
ronbrewer
06-18-07, 08:19 AM
I haven't installed the RealNav mod yet since I haven't come back from my current patrol. However, I'm planning on it sometime this week. I'm curious about the longitude issues. Reading through the threads it looks like the problem is encountered when east of GMT. If that is the case do you think the results will be better for patrols that start from the west coast of France (fall '41 and beyond)?
don1reed
06-18-07, 10:20 AM
Longitude:
Even without the aid of Celestial Navigation, the player can still navigate using Dead Reckoning to get to an Assumed Position within the sim, i.e., Distance in Nautical Miles = (Speed in knots x Time in minutes) / 60.
Make yourself a UT to Local Time Zone converter with whatever spreadsheet pgm you have. Its not hard to do. (Google: Time Zone Chart)
Van's Sun Almanac will work for SR & SS. These occurrances are based on when the sun is in the center of a time zone:
0-15-30-45-60-75-90-105-120-135-150-165-180 E/W. Each time zone is 15° wide, 7° 30' on each side of center.
You have to do the rudimentary simple math of adding or subtracting the time of SR or SS at your location from the center of the time zone of your assumed position based on van's sun almanac. If you're further west of the center of your assumed Time Zone, naturally, your SR or SS will be later. Depending if you are E or W of prime meridian and which side of time zone center determines whether you add or subtract.
You can also use the Sun Almanac to determine the Local Apparent Noon for the center of each time zone by subtracting SR from SS time, then divide the remainder in half, then add that half to SR to find LAN...then again, the rudimentary math as above.
When the sun is due N or S of your location, its noon.
In short, my advise is not to give up too soon on the mod. It needs a lot more eyes and players to do the testing.
Best of luck,
As I am still on patrol and want to install the mod after finishing it, I tested just a very little bit yet ;)
I measured how far WEST I am from Greenwich (1625km, so drawed a 270° line from there) and what the difference of local time to GMT looks like (exactly 1h). I wanted to do this a little bit more to see by myself how reliable the local time is and if I could use that to get an idea of my current longitude.
As I am still on patrol and want to install the mod after finishing it, I tested just a very little bit yet ;)
I measured how far WEST I am from Greenwich (1625km, so drawed a 270° line from there) and what the difference of local time to GMT looks like (exactly 1h). I wanted to do this a little bit more to see by myself how reliable the local time is and if I could use that to get an idea of my current longitude.
longitude (in km, per 1°) = (111.320 + 0.373sin²φ)cosφ where φ is latitude
:|\\
source: wiki
So where is the problem about getting longitude then ? ;)
The idea of real navigation certainly sounds interesting...
I'll have to read this thread thru in a little more detail. I guess the nagging issue I have in the back of my head is the fact that the game map is a distorted... how shall I say... pre-Columbus (i.e. flat world) map.
Does that not confound the trig? I would suspect dead-reckoning would be prone to very little great circle-type error.
Forgive me if it's already been addressed, I'll go back and read now...
If I understand you correctly, then it has already been dealt with by:
longitude (in km, per 1°) = (111.320 + 0.373sin²φ)cosφ where φ is latitude
The determination of the latitude says something about the angle in which the map should be "round" at a certain latitude value. The curvature of the world at this latitude.
If I understand you correctly, then it has already been dealt with by:
longitude (in km, per 1°) = (111.320 + 0.373sin²φ)cosφ where φ is latitude
The determination of the latitude says something about the angle in which the map should be "round" at a certain latitude value. The curvature of the world at this latitude.
The map is OK, it's a proper projection on flat screen. If you connect some points, they are exactly on a given meridian as they should, but the whole map should be about 50% width! The explanation why is in post #15 and the above formula.
I've got Vans reply, he's currently busy but still in the subject. Didn't have a clear mind to go though this yet:
You can still measure longitude, but you must be aware of the following.
- The GMT clock (lower right corner) locks onto to either Greenwich or the nearest Meridian (longitude line) to your position when you load/start a mission. This time remains your time until the next (save)reload/mission. Make allowances for this when reading the Sunrise/Set tables, and you'll find that you will probably get within 1 Degree accuracy.
- The local clock that appears above the GMT clock is only usefull for noting the hourly changes between this and the GMT clock. These hour differences occur at multiples of 7.5 Degrees (not 15 Degrees).
For example:-
Your GMT = 16:00 and your Local = 16:00.
Suddenly your Local = 15:00, which indicates that you're an hour behind GMT (or your last load position).
You're not actually an hour behind at this change but 30 minutes (horrible game bug).
Use these formulae for calculations.
Going West Longitude = 15 x (GMT - Local hours) - 7.5
Going East Longitude = 15 x (GMT - Local hours) + 7.5
Nice, thanks. This should help out. It's a little bit of a way around but that's no problem.
Something that might help:
At the end of my last patrol I tested how much my boat gets off course in bad weather. I hadn't really much time so I did some rudimentary test only.
Wind was coming from 312° by a speed of 15km/h. Excluding visibility it was the worst weather SH3 can produce. Here are my course settings, and how far I travelled and how much my final position differed from the estimated one.
Course 90°
after 10km: ~500m difference to North (so to the left)
Course 0°
after 10km: ~275m diff. to East
Course 180°
after 20km: ~75m diff to East (but more due to a slight error in the initial course setting because it was the same after the 20km's)
Course 270°
after 10km: ~600m diff. to North
Doesn't look quite like I would have expected it, I will redo it more precisely when I have more time for it. This should help set the right course in bad weather conditions so it should reduce the error when "real navigating" :hmm:
Doesn't look quite like I would have expected it, I will redo it more precisely when I have more time for it. This should help set the right course in bad weather conditions so it should reduce the error when "real navigating" :hmm:
This is nothing, when transiting for 1000 km in bad weather I have to correct course all the time. Check out with ctrl+click in x1024 how fast the boat gets of the course... I really wonder how I did it for the first time, when my position after several direction changes, was quite accurate in the end (1 screen). Maybe x256 doesn't generate such a big error? All my observations are while doing 7-10 knots. This is a serious problem because small errors on longer distances add up very quickly... it might be realistic but for the gameplay - transit - its very annoying.
This is nothing, when transiting for 1000 km in bad weather I have to correct course all the time. Check out with ctrl+click in x1024 how fast the boat gets of the course... I really wonder how I did it for the first time, when my position after several direction changes, was quite accurate in the end (1 screen). Maybe x256 doesn't generate such a big error? All my observations are while doing 7-10 knots. This is a serious problem because small errors on longer distances add up very quickly... it might be realistic but for the gameplay - transit - its very annoying.
Could you make a WCA course adjustment?
Couldn't you just calculate the error in your heading for longer distances too ? Just try the following:
Under a certain and constant (bad) weather condition, with lots of wind, set a straight course in any direction and compare your drift from the estimated positions after 10km, 100km and 500km, perhaps even 1000km.
Even if this drift has some exponential rate of growth, one should be able to estimate it. Always assuming that the surrounding conditions do not change of course. It should be not too hard to take all that into account when planning course, even if bad weather disturbs it. At least one can minimize the error with that.
Couldn't you just calculate the error in your heading for longer distances too ? Just try the following:
Under a certain and constant (bad) weather condition, with lots of wind, set a straight course in any direction and compare your drift from the estimated positions after 10km, 100km and 500km, perhaps even 1000km.
Even if this drift has some exponential rate of growth, one should be able to estimate it. Always assuming that the surrounding conditions do not change of course. It should be not too hard to take all that into account when planning course, even if bad weather disturbs it. At least one can minimize the error with that.
Unless you're going from calm winds to hurricane conditions there is no exponential growth in WCA (wind correction angle). As long as the wind vector is constant and your movement vector is constant it would be a steady WCA. Assuming constant wind and course hdg/spd your 10, 100, 500, 1000 km observations should yield a straight line.
Granted, WCA is a term more common in aero-navigation. In a naval sim, I haven't done any testing to see what would be required to offset a 15kt crosswind. I doubt they did any modelling of wind driven (or other) currents... but I dunno for sure.
don1reed
06-19-07, 01:31 PM
In real life navigation there is no way that mariners can quantify the errors of Tidal Current and Leeway caused by the wind.
Drift = speed of current
Set = Current's course
Leeway = Leeward motion of a vessel pushed by the wind.
Separately one can use vectoring to compensate on a course to follow; but, when both appear at the same time, the only way mariners can quantify their cumulative effect is by comparing simultaneous fix and DR positions.
-...-
Now, back to the ficticious world of SH3 & 4, sailing without dragging/dropping a course using the course icon.
The actual head of the sub is being sent off course during foul wx, it is not being pushed to leeward by wind or drifting due to current. Its as if the helmsman falls asleep, and the vessel takes another course. I guess its put in the game to resemble the effects of wind and current; but, the only known compensation so far has been to keep the High Speed TC around 128 or below, and be extremely vigilant trying to watch the miniature compass...which will drive one to drink.
The actual head of the sub is being sent off course during foul wx, it is not being pushed to leeward by wind or drifting due to current. Its as if the helmsman falls asleep, and the vessel takes another course. I guess its put in the game to resemble the effects of wind and current; but, the only known compensation so far has been to keep the High Speed TC around 128 or below, and be extremely vigilant trying to watch the miniature compass...which will drive one to drink.
I don't have any bright ideas how to compensate and the only way so far is to stick to the compass or constantly press = in peri or uzo view to check if we're on the exact course.
Eventually we could check out if that is possible to switch off in cfg that helmsman falling asleep (the error is enormous!) or reenable waypoint autonavigation just for transiting without any course shown, just the end point to keep it simple and start from there manually. Or if we figure out precise long/lats than it would make sense...
This game still requires imaging some things to keep it real but also I don't want to spend the whole time trying to keep my boat on course. Why me? What for do I have my crew?
Looks like mine from the first post ;)
http://www.militaria-house.com/schlesien-reisekarte.jpg
Ok, I finally installed the RealNavMod. I started my patrol out of St.Nazaire, my patrol area was commanded to be DT59. So I set course for the Southern Atlantic.
Weather is calm, wind speed is at 4km/h, some clouds but one can still see the stars.
So in the second night, I grabbed my sextant and wanted to do a quick latitude measurement. I found Polaris by finding Ursa Major and Cassoipeia, as described in the manual which came with the mod.
But strangely it really isn't at the amount of degrees it should be. I know that I am somewhere around 45°N because I can't have travelled so far yet. But when using the sextant as described I would get measurements of about slightly more than 60°N.
I made a screenshot which shows Cassiopeia. Ursa Major didn't fit on the screen.
As you can see, the horizon is even under this screen capture, so I would get an result definitly way more than 45°N if aligning the screen with the horizon.
Any Ideas what I'm doing wrong there ?
(At least the stop watch looks fine again, thx Hadrys :up:)
http://cip.uni-trier.de/%7Eschmidt/pol.jpg
Ursa Major didn't fit on the screen.
As you can see, the horizon is even under this screen capture, so I would get an result definitly way more than 45°N if aligning the screen with the horizon.
Any Ideas what I'm doing wrong there ?
(At least the stop watch looks fine again, thx Hadrys
Happy to hear that.
Maybe this is the problem with the camera file Van was mentioning? What mods do U have except GWX? You have a different control panel...
BTW i'm using a modified version now which allows to plot course if you ask your helmsman - intended to help in ports and long distance transiting in bad weather. Once my boat went off course nearly 90 deg in under an hour, so this is ridiculous.
Still don't know how to remove navigation tracks just to have final end points only.
In one of the other threads I read something about GWX compatibility when using RealNav. Poor Sailor posted his NYGM version of the camera.dat which was changed by GWX and confused something with the camera angles and gave incorrect readings of Polaris.
SH3 is still running, was too lazy to install the file and reload the game + savegame yet.
The different panel comes from the 6_dials_nygm22 mod. Using this and RealNav together I had to read the detailled mod description of RealNav because both mods need essential changes in menu_1024_768.ini. 6_dials was already installed so I took the modified version of the menu[bla].ini and inserted the [G3F I320] by copy&paste to get the draggable sextant to work.
I don't use any further mods which should interfere with this stuff, just some sounds, textures, OpenHatch and the likes.
BTW i'm using a modified version now which allows to plot course if you ask your helmsman - intended to help in ports and long distance transiting in bad weather. Once my boat went off course nearly 90 deg in under an hour, so this is ridiculous.
This sounds nice too. In this first patrol using RealNav there is still good weather, so I have no problems but I experienced your problems before when setting some manual intercept courses for example. In bad weather you get way off track and it's hard to compensate, if you rely on precision because you don't get your own position displayed by the sim than it's even much worse.
So far I travelled in a straight line out of St.Nazaire to my first course change waypoint. The track was about 980km this far and I got off course by ~5km (using ctrl+LMouse).
In one of the other threads I read something about GWX compatibility when using RealNav.
In bad weather you get way off track and it's hard to compensate, if you rely on precision because you don't get your own position displayed by the sim than it's even much worse.
So far I travelled in a straight line out of St.Nazaire to my first course change waypoint. The track was about 980km this far and I got off course by ~5km (using ctrl+LMouse).
Gut gemacht Her Kapitan! Manual plotting give a nice feel, but with those deviations it's impossible to keep on course.
I've mentioned that camera problem. I also have pure gwx + some skins, music etc and polaris is very precise. So I have no idea. We know so much by now but are still at the same point. I'll post thet assisted version later (just changed commands cfg).
Good. I will change something too. The RealNavMod disabled some features of the nav officer. In fact it disabled every status question he could gave you except for the current depht under keel. That's too bad because I miss the feature that he can tell you how far you can sail with your remaing fuel. I can't tell that by looking at the fuel gauge only so I will reenable this option.
But real navigation is nice. I finally have something to do, even if nothing happens in the game.
No clueless wandering in my room anymore while waiting for the SH3 days to go by ;)
I can't tell that by looking at the fuel gauge only so I will reenable this option.
I was thinking about, I'll reenable it in normal realnav and assisted. I could use it now... I'm going home, I'm just there. After hard beating (but the hunt was very fat) 20 knots in my VIIB and engines suck vast amounts of that black precious liquid.
I must admit that the problem with keeping course discouraged me, but lack of my sub on the map is good.
PS Flugzeug gesichtet, even didn't wonder just alarm, at 20 knots they disappeared under the surface in few seconds. 2 Huricanes 100km W from Brest? :|\\
Updated compilations, fixes some errors, added assisted mode, see readme. Check post #1.
I got the thing with the stars working. In one of the other threads about real navigation someone posted his NYGM version of the camera.dat. Now it seems to work allright for me.
My little patrol report using RealNav the first time so far:
Got out of St.Nazaire at Dec 16th 1940. Patrol area was ordered to DT59, West of Northern Africa. So I set course to 245°, 10.5kn.
Weather was fine till I reached the first waypoint 980km somewhere near the spanish coast. There we got into heavy fog and rain which kept going on for the next 10 days.
Course led me further southeast, had to go around Madeira, I took a safety course some kilometers further to the east then initially planned to not run into the ground because of the bad visibility.
Once I used Crtl + LMouse just to check my position, I will forbid me that on my next patrol ;) Course was good, I just overestimated my speed a little bit, so I hang a little bit behind. Perhaps this is a issue of TC, I used 256x or 512x at max.
When I finally reached the patrol area I made another Ctrl+LMouse check, the same about the speed again, otherwise our position was suprisingly exact.
On our way I cut down the TC every ~4-8 hours to correct the course again which slightly slipped off track from time to time.
I decided not to reintegrate the Nav officer feature that he tells me how far I can got with my remaining fuel. I just count the travelled km's and add them up.
So far in this patrol I travelled ~4141,1km. I have to take into account that stormy weather and recharging batteries will increase the fuel consume.
When I thought our 24h patrol in DT59 was over I had to CTRL+LMouse again because it said I didn't patrol 24 hours in that sector yet. I saw that I got a little bit out of the DT59 so I headed back south, finished the patrol.
Again it was a matter of higher speed than I though although I already took even half or quarter knots into account when making my calculations.
Suddenly in this night the sky cleared completely up again wind turned on to 13km/h though.
I did a reading of the stars and Polaris' position seems to be dead on now. So I'm looking forward to some real celestial navigation on the rest of the patrol and the ones that are still to come ;)
Here are 2 images of my current travelled course and the now functional sextant reading.
http://cip.uni-trier.de/%7Eschmidt/SH3/currenPatrol.jpg
http://cip.uni-trier.de/%7Eschmidt/SH3/nightsky.jpg
I got the thing with the stars working. In one of the other threads about real navigation someone posted his NYGM version of the camera.dat. Now it seems to work allright for me.
This is wired. Why with nearly same mods (important for us files should be the same) the behavior is different? Maybe check if one of your mods doesn't modify camera.dat?
Once I used Crtl + LMouse just to check my position, I will forbid me that on my next patrol ;) Course was good, I just overestimated my speed a little bit, so I hang a little bit behind. Perhaps this is a issue of TC, I used 256x or 512x at max.
On our way I cut down the TC every ~4-8 hours to correct the course again which slightly slipped off track from time to time.
During high wave speed can drop by 20-30%, but I'm curious with such a small course correction required. It would be good to edit some cfg's so the error would be very small to simulate helmsman keeping eye on compass constantly.
So I'm looking forward to some real celestial navigation on the rest of the patrol and the ones that are still to come ;)
Gut gemacht!! All my sextant readings are well so far, but how do you deal with longitudes?
PS my friend got me 2 teaching books about astro and sea navigation. Also reading Das Boot gives a nice clue how they did that!
This is wired. Why with nearly same mods (important for us files should be the same) the behavior is different? Maybe check if one of your mods doesn't modify camera.dat?
Maybe that I installed an older version of this mod, which wasn't GWX 1.03 ready ? I know I downloaded the GWX version too but don't know which one I delete and which one was left. Doesn't matter as long at it works ;).
During high wave speed can drop by 20-30%, but I'm curious with such a small course correction required. It would be good to edit some cfg's so the error would be very small to simulate helmsman keeping eye on compass constantly.
there I observed the speed gauge for a few seconds in 1x and then a few seconds under 256x TC to get an impression of my average speed.
The thing with the course can become very annoying, that's right. Didn't had that bad weather yet but there will be little progress in time if you constantly have to go back to 1x and correct your course. It was acceptable with 9km/h wind speed.
Gut gemacht!! All my sextant readings are well so far, but how do you deal with longitudes?
I never saw the sun since I made my very first course change, the weather was just too bad. I saved and quitted in the night I made my first real sextant reading and planned about measuring the longitude at the next sunrise. I'm going to use vanjast's Sun Almanac and the time difference at first.
Also reading Das Boot gives a nice clue how they did that!
I read Das Boot nearly 10 years ago, must have jumped over the descriptions of navigational efforts as I don't remember any of them in that book :roll:
I saved and quitted in the night I made my first real sextant reading and planned about measuring the longitude at the next sunrise. I'm going to use vanjast's Sun Almanac and the time difference at first.
I read Das Boot nearly 10 years ago, must have jumped over the descriptions of navigational efforts as I don't remember any of them in that book :roll:
I've just found on my HDD another almanac, don't know how I got it but it was a year ago. It gives SR/SS during war years but only for 51°N... It shows some diffs I think.
almanac39-45.pdf (http://mrhadrys.com/silenthunter/almanac39-45.pdf)
I haven't read Das Boot yet but in the movie it was rather omitted, but here they often take star fix, plot course etc. Just like we do it :D
Also I've restored GWX weather to stock SH3 stock settings and now it's raining far less. Fog, overcast, heavy waves throwing your boat in all ways yes! but the visibility is far better, it became more playable but also very hard to recognize targets far away in those conditions (smoke on the dark horizon etc). Cool :|\\
Thanks for sharing. Your almanac seems indeed a bit different but this is only a matter of minutes. I don't know whether that would hurt our measurements because they aren't that precise anyway.
How did you go back to stock SH3 weather ? Using SH3 Commander ? I think I remember such an option but can't check it right now.
Thanks for sharing. Your almanac seems indeed a bit different but this is only a matter of minutes. I don't know whether that would hurt our measurements because they aren't that precise anyway.
How did you go back to stock SH3 weather ? Using SH3 Commander ? I think I remember such an option but can't check it right now.
Donno either, maybe during the weekend I'll try to figure out those longs.
You're not browsing subsim carefully especially that your replied there :sunny:
http://www.subsim.com/radioroom/showthread.php?t=117081
:up:
Sometimes I just write what comes to my mind.
I will modify the weather a bit but won't set it too jumpy. Sometimes it feels nicer if a storm clears up after 1-2 weeks instead of having different weather every 2 days ;).
ronbrewer
06-22-07, 12:21 PM
Hello Hadrys/ichso,
I've been following your conversation very closely these last few days since I'm getting ready to install RealNav on my system. I currently run just GWX 1.03 but have downloaded another mod that will remove the tails of radio contact reports on the map. I plan on installing this mod along with RealNav and start using the sextant.
I'm curious about the issue with the camera.dat file. Did you find out if the problem with the location of Polaris was due to GWX 1.03 modifying camera.dat or was it a different mod? Also, I've been using 1280/1024 resolution and I'm wondering if I need to drop that to 1024/768 for the RealNav mod?
Thanks for the help,
Ron
I'm curious about the issue with the camera.dat file. Did you find out if the problem with the location of Polaris was due to GWX 1.03 modifying camera.dat or was it a different mod? Also, I've been using 1280/1024 resolution and I'm wondering if I need to drop that to 1024/768 for the RealNav mod?
Ron
Hi Ron,
I wanted to check the filesize or other stuff about my current Cameras.dat and compare it to the details of the Cameras.dat of stock SH3. But I was surprised that there wasn't such a file in the ...\data\Library\ folder of my older stock SH3 Backup.
Perhaps it is loaded from some archive on the SH3 DVD on startup and GWX introduced some extensions to it ? And NYGM made changes to this file too but not in a way that disturbes the sextant readings ?
Anyways, the NYGM version of this file is the way to go.
http://www.subsim.com/radioroom/showthread.php?t=114812&page=4
Poor Sailor uploaded his Cameras.dat there.
http://www.subsim.com/radioroom/showthread.php?t=113975&page=3
This is the thread (Even the same es above ? Too many browser tabs confusing me right now) where they explained how to create the scale for a sextant in general and what needs to be done to get it working in 1280x960.
I never cared about that as I play in 1024x768 but it seems like there isn't any other version for 1280x960 right now.
Much fun sailing and navigating.
Bye, i. :)
ronbrewer
06-22-07, 03:07 PM
Thanks for the links, ichso. I'll give those a try for the RealNav mod install.
I think there are some more issues I don't get along with yet.
At first is a correct speed estimation. I took my Latitude reading at 00:00h and set course 0° from there on. I tried to calculate the kilometers which I would travel in the next 24 hours, so I watched the speed gauge carfully and it was almost permanently at 10.1 knots (7km/h wind speed).
But when I took the next Latitude reading after 24 hours I hadn't travelled my calculated 428km but ~450km. This would have made an average speed of 10.9knots.
If you watch the speed gauge in 1x TC the average speed seems at least 0.5kn less than if you watch it at 256x TC. This is still a little bit strange. The error should be even bigger at higher speeds and with higher wind speeds too.
The other thing: I don't know if that occured before but the navigation officer doesn't report the correct weather all the time. In the worst case he didn't recognize any rain for days while it came washing down on me the whole time.
Despite that everything is working fine. I still didn't encounter ANY other vessel than the destroyer which let us out of St.Nazaire at the beginning of the patrol, but at least that makes the navigation easier when not interrupted by some convoy attacks or something ;)
don1reed
06-23-07, 07:29 PM
In real life, naval ships run a 1nm degaussing range.
It does several things:
It Demagnetizes as well as it is a timed run at x speed so they can tell how much marine growth will hinder their speed. It also allows the navigator to make adjustments. The run is made both leaving and returning to port.
They also learn how many rpms to make x speed during the run. It greatly assists in Dead Reckoning.
It might do well to mark off 1852m range or multiple thereof and time it as you leave port to get better DR estimate.
This is getting interesting, don1reed I really appreciate your posting!
I was trying to calculate longitude and I'm confused. My current position would be a little west from Reykjavik approach and from Encarta it looks like 64°15N 22°50W. Latitude fits very nice as usual however I had to measure Polaris to a star below and from that star to the horizon, it worked perfectly. Now:
longitude = (game sunrise @ 8:34 28 Feb 41) - (gmt @ 7:03) / 4 = 22,75° = 22°45W
So it's veeeery accurate. But if we consider stupid clock behavior mentioned by Van... doesn't make any sense. Maybe this is another game version/mod issue? My clock looks like gmt, local time -2, I'll try to check every other SR/SS. Unfortunately I didn't take time notes before saving/loading...
don1reed
06-24-07, 01:20 PM
Just 5nm off...not bad. IRL its easy to see that far at sea. Nice going:up:
In SH4 I'm trying to use the Obs scope as a sextant. It has range of movement ~90°...don't know if you have tried the Obs scope in SH3.
In SH4, the lens view at low magnification allows 32° field of view, then when angled straight up it allows field of view from 90° down to 58°. Trouble is that missing 26° in the middle of the field of view. A lotta stars cannot be measured or referenced to the horizon. It would be nifty indeed if the Obs Scope could also be used as a sextant within these two SIMS.
Your method of "stair-stepping" from star to star is dang inovative. Well done.
All the best,
Mav87th
06-25-07, 12:08 AM
If anyone of you see Vanjast. Tell him that i got the sextant working draggable in SH4 now....
http://www.subsim.com/radioroom/showthread.php?p=575113&posted=1#post575113
Just 5nm off...not bad. IRL its easy to see that far at sea. Nice going:up:
In SH4 I'm trying to use the Obs scope as a sextant. It has range of movement ~90°...don't know if you have tried the Obs scope in SH3.
Your method of "stair-stepping" from star to star is dang inovative. Well done.
Just checked as I'm still around my prev position. Needed to do 3 star-steps to measure Polaris with ObS but it fits exactly to my previous measured! Nice one when it's midnight and you cannot surface.
But there is another problem with longitude. I went east towards Reykjavik from my last measured position. Local time changed to -1 after making about 45km east (111km in SH3 is 1°E/W) than I took a note of sunset at 17:05 28 Feb after traveling about 0,5°E. If you compare it to the GMT SS it's like 4,5°W...... This clock is really wired and I don't get it. My prev measurement was just lucky? Also Vans rule to 15x (game time - local time) - 7,5 worked only there, as it doesn't include minutes. Every time we're getting somewhere there is also another problem, ehhh
Best regards guys
This clock is really wired and I don't get it. My prev measurement was just lucky? Also Vans rule to 15x (game time - local time) - 7,5 worked only there, as it doesn't include minutes. Every time we're getting somewhere there is also another problem, ehhh
I read somewhere that the SR/SS times are somewhat random. At my first time I tried to get longitude it was relatively precise too. After travelling north for 24 hours it didn't fit at all anymore.
And you cannot wait everytime to cross a marking where local time switches from -2h to -1h difference for example. I think is still too unreliable.
don1reed
06-25-07, 07:31 AM
After travelling north for 24 hours it didn't fit at all anymore.
Perhaps we must interpolate for our assumed LAT:
Lets say we're approx 38°N on 5 APR 2007, part of our Assumed Position (AP).
Below is a page from modern Nautical Almanac. Note that I've boxed in SR times and also Latitudes above and below our AP.
example of interpolation:
38°N is 3/5ths between 40N and 35N, and the difference in time for SR is 4 minutes; then, 3/5 x 4 = 0:02:24. We subtract 0:02:24 from 05:42:00 = 05:39:36, the approx time of our SR at 38° N Lat.
You can do the same thing with Van's Sun Almanac.
http://i77.photobucket.com/albums/j42/donhreed/2007dp.jpg
After travelling north for 24 hours it didn't fit at all anymore.
Perhaps we must interpolate for our assumed LAT:
Good idea, should increase our accuracy a lot but when interpolating for 64°N that would give sunset @ 17:15 and my ingame time was 17:05 so it's even worse. It should be at 18:52 to indicate that I've traveled 0,5°E. The difference is way to big. I think it's something with the damn clock. I didn't notice if with local time change also something happened to the gmt clock. I'll go back west to my previous position and recheck when the time changes and SR/SS times... no better ideas.
don1reed
06-25-07, 08:21 AM
You have a very valid arguement.
Another test we must make is to see if the UT and Local clocks in SH3 change when we precisely cross TimeZone boundary. Does the clock change at the middle of the TZ or does it change at the boundaries, i.e.,
7° 30' W......000°......7° 30' E......015°......
|..................|.................|
here......or....here?
Another thing to note that IRL SR and SS occur when the UL is flush with sea level, see pic below. However, the Devs have made SR/SS at the time the Sun is already half out of the water. (When red light goes on/off).
http://i77.photobucket.com/albums/j42/donhreed/srss.jpg
So, a few adjustments must be made to get the navigational consistancy we need.
You have a very valid arguement.
So, a few adjustments must be made to get the navigational consistancy we need.
I must say that all this is nice fun and interesting learning! I was thinking about problem but gave it up after reading Vans threads. It might be possible that if now I'm at 64°N that real SR/SS might take a lot longer. If I get it right I should measure with sextant those 12° and just wait till only that portion of sun "is sticking out of the water"? I'll try to check it all later. Just stick for some time near Reykjavik for the readings as I still have 2 eels aboard :arrgh!:
It would be really nice to get it working properly. It is fun playing out the navigational efforts but if one cannot estimate the longitudes good enough it's a little pointless in the long run.
Thanks for all the work and research you've invested so far. I hadn't time to play since a few days now. But I will go on testing in a few days so that we come to either a conclusion how the longitudes can be measured precisely or at least that it can't be done to a satisfiying amount.
In that case it might be better to just turn the mod off again :/
don1reed
06-26-07, 09:15 AM
"Timing is Everything", its been said, but, no where more important than when used with Navigation. :)
Alright...
Here's two pics which may shed a little light on our problem.
1st pic is of 6.9.1939 Uboat posit AP 54° N, 008° E. Zone Description (A -1)
Note that the upper time is called "LOCAL TIME" (06:43)..and the lower time in the white box (05:43) is not labeled. I presume everyone thought the time in the white background box was UT (GMT). Right?
Here have a look...
http://i77.photobucket.com/albums/j42/donhreed/Wrongtime2.jpg
...Now...
Using StarCalc and a real life navigation program, "Navigator" to determine SR at my location, check out the UT times compared to the Times in zone Alpha -1:
http://i77.photobucket.com/albums/j42/donhreed/WrongtimesinSH3.jpg
This shows me that the time designated "Local Time" in the Sim is one (1) hour off, and the time everyone thought was UT is also aflicted with that 1 hour discrepency.
Time ...forgive the pun...for an adjustment.
Edit: The only thing correct about the two times in the first pic is that there is a one hour difference between UT and Local time at my geo coordinates. So, the time in the lower white box is in fact the real LOCAL TIME, I must then resort to my "Local Time to GMT conversion chart", as I've always done.
Same ole, same ole...
...anyway...here's how my SR unfolded:
Using Sun Almanac that came with RealNav
Interpolate:
60-N
50-N There are 10° difference I'm about 54°N 4/10. There are 17 min. difference between the SR times for the two Latitudes.
4/10 x 17 = 0:06:48, subtracted from the SR time for 50N 5:21 - 0:6:48 = 5:14:11.
SR occurred at 05:43:06 (local) - 5:14:11 (local) = 0:28:55 / 4 = 7° 13'.
Middle of my time zone (15° E) - 7° 13' = 7° 47' E (my current longitude)
Hey don, that is some very valuable information! :up: I'm gonna try that this evening.
One thing about your SR time there: How did you measure exactly this 05:43h ? Your still on redlight and the sun is not to be seen on the above screenshot yet.
I used to wait until just a glimps of the sun was seen for the SR time, that was also the same moment as the redlight gets turned off.
don1reed
06-26-07, 11:47 AM
How did you measure exactly this 05:43h ?
I got that time from "StarCalc" as the SR for assumed position (AP) 54° N, 008° E. That time was also in sync with my Navigator pgm as SR from my posit.
I've GWX and NYGM on my HD and this time I was using GWX which doesn't show the sun very well through the scopes or binocs. When on the bridge the sun shows up too well and very bright where I cannot see it's outline at all...needs sun filters like real sextant.
How did you measure exactly this 05:43h ?
I got that time from "StarCalc" as the SR for assumed position (AP) 54° N, 008° E. That time was also in sync with my Navigator pgm as SR from my posit.
I've GWX and NYGM on my HD and this time I was using GWX which doesn't show the sun very well through the scopes or binocs. When on the bridge the sun shows up too well and very bright where I cannot see it's outline at all...needs sun filters like real sextant.
I'll go through what you posted, sounds interesting but I'm losing my nerves quickly. Today I've tried to navigate from Lorient. Flat sea and even before going NW i was way off. 1-2 hour corrections didn't change anything and it was like 180-181-180°... so I'm pissed because I can do everything precisely and it doesn't matter at all. Damn helmsman. Need to fix him (it).
Weird or not ?
My current patrol:
Jan 1st, 1941. Latitude at midnight: 40°.
SR/SS Almanac from the mod says that I should get a SR at 7:22 local time for 40°N and 7:58 at 50°N.
By taking speed (10.5kn) and course (000°) into account, my position at SR would be at lat. 41,5°N.
Difference for SR times from 50°N to 40°N: 36min
1.5/10 * 36 = 05:24m.
So SR at 41,50° would be at 7:27:24.
7:58:00 - 7:27:24 = 0:30:36.
0:30:36 / 1.5 = 20.333...
which is my current longitude.
Don't know if I forgot something. I didn't take into account that the changes of the time difference between local and GMT occur at the middle of the timezone.
A new attempt 2 days later:
Lat: 47.5°N
So referring to the Van's Sun Almanac and interpolating between 40°N and 50°N again I should have seen the sun rise at 7:49 ( 8:49 loacl time at 15°W)
I tried to use the 'red light off' moment as my local SR time. this was at 9:10.
So I am 21 minutes behind the SR time for 15°W which would mean that I am ~5° farther west, so at ~20°W, which would meet my real longitude well (still being ~20.5°W).
I am not sure what to take as my referring point for the SR yet but the moment when red light turns off (= sun is to be seen by half of it's amount) fits well in this example. I will test this a little further tomorrow.
Mav87th
06-27-07, 08:34 AM
A new attempt 2 days later:
Lat: 47.5°N
So referring to the Van's Sun Almanac and interpolating between 40°N and 50°N again I should have seen the sun rise at 7:49 ( 8:49 loacl time at 15°W)
I tried to use the 'red light off' moment as my local SR time. this was at 9:10.
So I am 21 minutes behind the SR time for 15°W which would mean that I am ~5° farther west, so at ~20°W, which would meet my real longitude well (still being ~20.5°W).
I am not sure what to take as my referring point for the SR yet but the moment when red light turns off (= sun is to be seen by half of it's amount) fits well in this example. I will test this a little further tomorrow.
When you write 47.5*N is that 47*5'N or 47*50'N ? I assume the later
don1reed
06-27-07, 08:47 AM
Its a hard grapple, I know. For me, the frustration level mounts daily...not good for an old fart with bad ticker :D
Something worth knowing:
1)Those SR/SS tables, both van's and IRL are in "LOCAL TIME". Its up to the mariner to compute UT (GMT).
2) Are we taking into account DayLight Time/DayLight Savings Time ?
3) I found out yesterday, while sailing NW in U.47 (AP 55° N, 7° 31' E), that the lower (white background) clock in SH3 dropped back one hour when the boat crossed meridian 7° 30' E, the boundary line between Prime Meridian 000° and 015° east.
edit: I'm going to replay this, just to make sure....
When you write 47.5*N is that 47*5'N or 47*50'N ? I assume the later Yes, sry, I meant 47°50'N :roll:
1)Those SR/SS tables, both van's and IRL are in "LOCAL TIME". Its up to the mariner to compute UT (GMT). Am I missing something again ? Van's SR/SS Almanac gives no Information about the longitude for any specific SR time. So it's the local time of what local point ? The only thing these SR/SS times can refer to is the GMT or am I wrong there ?
As I wrote in my previous post, the last time I tried to calculate my longitude I just used the time difference between the SR time from the almanac and the time my red light got turned off. At that moment I read the time from the upper clock, the one that pops up when you point with the cursor at the clock.
This difference was about ~1.3 hours (it was 9:10, the SR from the almanac read 7:49). And that calculated into my longitude ~20°W which was correct.
So I have the theory:
3) I found out yesterday, while sailing NW in U.47 (AP 55° N, 7° 31' E), that the lower (white background) clock in SH3 dropped back one hour when the boat crossed meridian 7° 30' E, the boundary line between Prime Meridian 000° and 015° east. That this doesn't matter for the SR/SS times you get from the almanac if you use the points of "redlight on/off". This seems to be exactly the time when the sun sticks half out of the water and maybe just that little time difference to local time to even out the effect that the local time switches not at 15°W/E, 30°W/E, ... but at 7°50'W/E, 22,5°50'W/E, ...
I will test that for some different longitudes this evening to see if it fits then too as it did yesterday.
don1reed
06-27-07, 11:08 AM
Am I missing something again ? Van's SR/SS Almanac gives no Information about the longitude for any specific SR time. So it's the local time of what local point ? The only thing these SR/SS times can refer to is the GMT or am I wrong there ?
Since the globe is, for navigational purposes, considered round, then its been established that the sun rises and sets at the same time in each of the 24 time zones.
When the sun is over my RL meridian, its RL noon in local time. When that occurs, it happens to be around 1800 GMT. There is a 6 hour difference between my RL local time and GMT for my RL location. Based on seasonal earth moving events (earth 23.5° tilt), SR/SS changes in timing perspective depending on your Latitude. Thats why the times are different day to day, month to month, etc.
If you take another look at the sun almanac you will notice that every SR and SS occurs at around the same time, i.e., SR in the morning and SS in the evening. If the table were based on GMT then the SR/SS times would all be different.
example:
Say you and I are stationary; I'm at 55-N 8-E and you're at 55-N 90W...
Based on the Almanac, the sun will rise and set at the exact same times...except your SR/SS will occur 6.53 hrs. later
http://img523.imageshack.us/img523/1360/55nbi6.th.jpg (http://img523.imageshack.us/my.php?image=55nbi6.jpg)
As the earth rotates, the sun rises the same time locally as seen from the same latitude.
The method I mentioned, using the moment when red light turns off as your SR time, seems to work well.
Just know your latitude as precise as possible. From Van's SR/SS almanac get the current local SR time by interpolating between the next bigger and next smaller given lat.value there.
Then just wait for the exact red-light-off-moment (minute wise) and get the difference from the above calculated SR time. This time difference is needed in hours, for example are 75 minutes of time difference to be used as 1.25 hours.
Multiply that number by 15 and that are the degrees your off from Greenwich.
I worked myself from the coast of Northern Africa up to Scotland and from there back to St.Nazaire with very good results of position calculations.
Had no ship encounter on the hole patrol though, nearly ran out of fuel before returning to base :shifty:
Mav87th
06-28-07, 12:58 AM
We are basicaly working with 3 "times" here
BASE TIME: Gameclock (in SH-4 thats easy as there is only one! In SH-3 Don's findings shows that its NOT the one with white background)
GMT: Well that says it self. Van's SR/SS almanac is GMT times for SR/SS at 10 different lattitudes for each date all year in 1939 (Valid for all the war years)
LOCAL TIME: The "missing link". The time we need to convert the two others into in order to make our calculations. (Or if you want to skip that then convert all the SR/SS's into BASE TIME or vicaversa GMT's to BASE TIME)
Those convertions are what i ****ed up the most in the start, now im starting to get the hang of it. Just crossed the I-dateline in SH-4 after a great start from PEARL. First Sunset at around Lng 177E sat me 30nm off my real Lng. Im now waiting for the stars to shine through so i can take a fix on a couple of low stars. (I have found when using stars hanging low on the horizon to be most precise).
The fast and easy thing would be to shoot Polaris and take that reading for granted for Lat., witch is the way i do it when crossing the pond on the long jurneys. Then ocationally i take a 6 star fix and calculate the position from the star GP's etc etc. with Navigator. That takes me within 15nm most of the times (when im controling it)
Redlight time in SH-4 is DEFINETLY the correct SS/SR time - only thing missing is seconds in van's almanac to make it more precise, but i can get that from Navigator.
It's correct that you need to know your Lat. pretty precise, but if you sail a heading for an amount of time you are not going to end up to far from where you plan, unless you fastforward x1024 or more. In that case you have to sit "watch" at the helm and click it every time it strays from the course.
One thing that is still missing (I think) is a good speed conversion chart for the various weather conditions.
I found that looking at the speed gauge and trying to estimate the average speed from that differs too much from the average speed unter 512x TC so this would still result in wrong position markings by tracking course.
A really complete chart would be to huge I think. Then one would have to write everything down for each uboat available and with each combination of speed effecting upgrades available for it.
Maybe there are just some factors by which the sub's maximum speed is reduced under certain wind strenghts, which wouldn't be all surprising.
For example: In early 1941 I travelled many days in my VIIC under wind speeds of 9. Some time I calculated a speed of 9,8kn from my course, which would be 18,47km/h. This was good enough to use to travel in any direction as long as the wind stayed at 9.
So it seems as this would really only depend on the wind and a little helpful table would be nice. So that one could just read the values he needs.
don1reed
06-28-07, 07:57 AM
Van's SR/SS almanac is GMT times for SR/SS at 10 different lattitudes for each date all year in 1939 (Valid for all the war years)
Van's sun almanac and SR/SS MR/MS tables on the right hand pages of the Nautical Almanac are in Local Mean Time, not GMT.
See:
http://www.irbs.com/bowditch/pdf/chapt18.pdf
section: 1809 Local Mean Time, paragraph 2
Today I'm testing my patience as not much to do at work, probably everybody's waiting for US Interest Rate Statement...
Stormy weather but managed to pick a brake in overcast. I'm halfway between Ponto Delgada and Lisbon CF65.
Trying to nav without that silly helmsman and correcting my course constantly at max x128... Calculated speed deviation and checking my positions every 9 hours by sending a report to BdU (it gives your grid) so it fits very nicely when I should enter next grid. Also did some math to calculate my lat at SR time (didn't catch SS though). As checking with the maps lat looks fine - 38°N. I like that part very much because lat fits very well, I'm on 215° course so my adjustment for lat was also not that simpe. Also I don't align my bottom of the screen but give it some space to precisely adjust sextant.
Now the hard part. SR was at 5:34 (4:34 local as I should be between 7,5°W and 22,5°W). Which value should I take, GMT? With GMT that gives 1h 6 minutes difference so 1,1x15= 16,5°W and it also looks fine! Impressive Ichso. Very simple method and probably you proved it to be right.
Thanks.
I agree with don1reed, that the SR SS tables give the SR/SS times for local time, not GMT. But then his older post can't be right that the clock in the rightmost low corner shows the local time. Otherwise the SR time you can calculate easily by knowing latitude and using the almanac would match the time which is shown by the clock in the right lower corner (white background).
I'm going to try this method of position marking only on my next patrol and won't rely on cheating. I want to see how far I get off course then.
It's a little annoying that you need very precise latitude measurements and at best very precise SR/SS times (calculated from almanac and measured) too in order to get a good longitude value. If one trys to intercept a convoy, reach a certain destination or something like this all those factors can lead easily to a failure. So some pratice is needed ;).
Also I don't align my bottom of the screen but give it some space to precisely adjust sextant.
That's a nice idea, could make it easier. Will try that too.
If one trys to intercept a convoy, reach a certain destination or something like this all those factors can lead easily to a failure. So some pratice is needed ;).
That's a nice idea, could make it easier. Will try that too.
But that's the whole point! We are that nasty kind of guys who love to make things harder. Check out this thread http://www.subsim.com/radioroom/showthread.php?t=117480.
Sextant: I didn't find any difference if aligning screen with horizon or not. if it is under bottom panel it's ok. Also I'm now using 1680x1050 and stock sextant works ok, it's stretched like it should.
Is my calculation right? Interpolated lat, (right corner game time - almanac ) in hrs * 15. Or am I missing something? You produced a lot of stuff with Don and it's quite confusing.
Is my calculation right? Interpolated lat, (right corner game time - almanac ) in hrs * 15. Or am I missing something? You produced a lot of stuff with Don and it's quite confusing. I'm still a little confused about that two clocks we got in the game.
But as it worked out so far I'm pretty sure that the lower right clock (white bg) gives GMT.
Don's suggestion (I think it was him) to interpolate between the latitudes from the almanac is necessary. The only thing we might have done wrong might be to take the wrong moment for the local SR so far. Your calculation looks good.
As an example:
Let's say your latitude is 46°N, your at Jan 1st, 1941.
- Looking in Van's almanac the SR times are 7:22 for 40°N and 7:58 for 50°N so
at your lat. the SR should be at ~7:43.
- You observe that red light gets turned off at 9:07 which means a difference of 84
minutes = 1.2333... hours.
- Multiply 1.233333... * 15 = 18.5 (°W). Your longitude.
But that's the whole point! We are that nasty kind of guys who love to make things harder. Check out this thread http://www.subsim.com/radioroom/showthread.php?t=117480. I still need to print this cool thing. But it might make things even a little easier as there are no errors by marking something on the map when using the wiz-wheel.
Trying to nav without that silly helmsman and correcting my course constantly at max x128... The last time it felt (at wind speed 15) that at TC 128x I got more off course than traveling at higher TC: 256x and 512x. Perhaps my PC is to slow and drops computing course errors at higher TC's ? :hmm:
I'll just added vans map to check out more precisely in game and it looks like Vans longs and lats are fine but my lat readings are varied 2°S from my plotting. Just pressed ctrl+click which I wouldn't like to do but there was no other way. It turned out that after 600km in heavy storm and lots of diving. I'm ~7km to far mainly, because the weather got better for some time and I didn't compensate. My current long fix from last SR is precise despite 2°S lat reading... it couldn't be so much different or I'm measuring it in the wrong point of horizon? It's not that obvious. I'm gonna take a Polaris fix tonight as I'm patrolling (drifting) in CF91. I'm not gonna compensate for ctrl click, we'll see what happens next.
PS I'll try to redo the grid with much thinner lines, Vans are HUGE.
PS I'll try to redo the grid with much thinner lines, Vans are HUGE.
:rotfl:
Especially in the highly zoomed out views ;)
The thing about the latitude readings is one I dont trust that much yet either. There are many factors which can disturb the reading. If Polaris is port or starboard from your heading then it's sometimes really hard to align the horizon with your screen, it will always be leaning to one side. One other thing is that the view gets distorted by the projection of the sky texture if Polaris is not in the center of your screen.
I have to read something about shooting the sun with the sextant again. Was in some thread about the mod.
What I'm going to test later is at what point the sun has to be in order to be considered as high noon. Perhaps this is possible with the sextant too ?
This would give us an alternative possibility to measure longitude.
What I'm going to test later is at what point the sun has to be in order to be considered as high noon. Perhaps this is possible with the sextant too ?
This would give us an alternative possibility to measure longitude.
Would be useful.
Ok I seems that I can't do 2+2=4... Until I haven't clicked ctrl and turned on Vans map it was fine. I'm standing still. SS was at 20:15 (-1 local time). With sextant I've managed to measure Polaris an hour later at 36°N. At midnight we've got brown clouds and thunderstorms (looks cool) but not a single star arrrrgh!
Position from the map is 37°... I should probably even subtract 1° from my reading as Polaris is 1°N (?) so I would get 35°. I've calculated for 35,36,37 and getting results like 12° or 25° if I add 1 hrs. I should get 17,5°W!! 3 Juli 41, almanac 19:05 19:32 = 27*0.7 (37°N) = 19:24.
20:15 - 19:24 = 51' / 60 = 0,85 hrs * 15 = 12,75°W (already you know it's wrong as the value must be >1 and exactly 1,16666 hrs = 1h 10' difference = SS at 20:34.
So anything doesn't fit here. In game we're still -1hrs between 7,5 - 22,5°, IRL -2hrs between 15 - 30. I can't see any obvious compensation here. Maybe reloading the game messed up something with the clock??? Or am I blind? Either way I'm gonna continue my patrol with manual plotting.
Do u have skype guys? Maybe we could conference... BTW my name's Adam as we already produce those amounts of stuff here ;)
PS I could try to make timezones over the game map (7.5-22.5) as a little brighter areas. Just not to bother but might be useful??
Hm, I never tried that method with SS times. But I had issues measuring longitude with it too. It first was several degrees off and I tried to play around a bit with the values (latitude and time). Finally I used ctrl+click and saw that I was more off of my estimated position as I thought and using my cheated latitude everything fitted again.
This was frustrating and I planned to be more careful with my dead recogning the next time. I will test the sunset longitude too when I fire up SH3 in a few minutes.
PS I could try to make timezones over the game map (7.5-22.5) as a little brighter areas. Just not to bother but might be useful??
Why not, sounds nice as long as they don't disturb the overview. But it can't get much worse than now with Van's huge long/lat lines :roll:
Do u have skype guys? Maybe we could conference... BTW my name's Adam as we already produce those amounts of stuff here ;)
Nice, Thomas :)
I'm afraid Im a complete skype/teamspeak outsider though:oops:
Mav87th
06-29-07, 06:05 AM
I have tried to alter the sextant a bit. Im using it from the deckgun pos. as that one are stabilized (altered the AngularAngle to 75 to have 60° from bottom to the top of the screen - VALID FOR SH-4) and thus much easier to shoot stars from.
I then noticed (as the deckgun station unzoomed has a red cross in the center of the screen) that 30 degrees were 1 deg to high compared to the center of the screen. I have now made the Sextant centered on 30° and then similair on both sides of 30°'s.
The sextant I have altered can be found:
http://files.filefront.com/KF+SextantXtga/;7915400;;/fileinfo.html
It is correct that Polaris should have 1 deg. substracted from its sextant reading (or at least aproximatly 1°)
Mav87th
06-29-07, 06:08 AM
Van's SR/SS almanac is GMT times for SR/SS at 10 different lattitudes for each date all year in 1939 (Valid for all the war years)
Van's sun almanac and SR/SS MR/MS tables on the right hand pages of the Nautical Almanac are in Local Mean Time, not GMT.
See:
http://www.irbs.com/bowditch/pdf/chapt18.pdf
section: 1809 Local Mean Time, paragraph 2
I stand corrected Don :oops: Allthough GMT is a Local Mean Time.....:|\\
I have tried to alter the sextant a bit. Im using it from the deckgun pos. as that one are stabilized (altered the AngularAngle to 75 to have 60° from bottom to the top of the screen - VALID FOR SH-4) and thus much easier to shoot stars from.
I then noticed (as the deckgun station unzoomed has a red cross in the center of the screen) that 30 degrees were 1 deg to high compared to the center of the screen. I have now made the Sextant centered on 30° and then similair on both sides of 30°'s.
The sextant I have altered can be found:
http://files.filefront.com/KF+SextantXtga/;7915400;;/fileinfo.html
It is correct that Polaris should have 1 deg. substracted from its sextant reading (or at least aproximatly 1°)
Thanks! I recognized thist problem too yesterday.
I worked around it by holding the sextant a certain (and very specific) amount to the left. The slightly distorted view at that position seemed to produce correct polaris readings then. Here's a screenshot of how I did it:
http://cip.uni-trier.de/%7Eschmidt/sh3/ds.jpg
don1reed
06-29-07, 04:11 PM
http://i77.photobucket.com/albums/j42/donhreed/GMTConverter.jpg
Thanks! I recognized thist problem too yesterday.
I worked around it by holding the sextant a certain (and very specific) amount to the left. The slightly distorted view at that position seemed to produce correct polaris readings then. Here's a screenshot of how I did it:
I've moved it even more to the left but still can't subtract 1° and not so sure about those numbers. Using flak camera doesn't change anything. Maybe I'll try 75° verstion. However getting my lat from ctrl-click and Vans map in SH3 i get 2,5°W instead of 4°W... so I'll just keep on plotting and enjoy flat sea, cloudless sky not worrying about sextant and try to sink something using slide ruler (great thing)!
Need to finally do my 14th patrol because from 2 weeks (?) I've been starting it all over again to try something, navigate, test mods etc and honestly I should restart it again as my crew needs still few fixes which can be done in port only.
I've moved it even more to the left but still can't subtract 1° and not so sure about those numbers. Using flak camera doesn't change anything. Maybe I'll try 75° verstion. However getting my lat from ctrl-click and Vans map in SH3 i get 2,5°W instead of 4°W... so I'll just keep on plotting and enjoy flat sea, cloudless sky not worrying about sextant and try to sink something using slide ruler (great thing)!
This is still a little bit strange. On my current patrol it seemed as I had to hold the sextant a bit to the left to get an accurate reading and as I travelled ~10° north it was good again.
Also, in bad visibility the longitude method gets something inaccurate (the measurement was about 2° off).
But that wouldn't be all unrealistic because it should be very hard to determine the exact time of your local sunrise if you can't see the sun because of clouds and fog ;).
Then I decided to just let it go with ctrl+click and do the best I can to navigate and see where I get with that.
I soon got a contact report for a large convoy SW from GB because of the heavy fog I have to approach it very carefully to not run into any escorts but I'm almost there.
ronbrewer
07-02-07, 12:08 PM
I finally installed RealNav this weekend. I was at the end of a patrol on the Spanish coast in March, 1940, and decided to dock at the ship named Bessel for resupply. I installed the files for RealNav, the camera.dat file, and the mod that removes the tails of radio contacts.
I have to say that this is very interesting using the sextant on Polaris and interpolating the SR/SS times. I noticed it was very accurate at the beginning when I was leaving Spain. However, I started to get errors of around 60nm while heading toward 15 degrees West. I have found that Polaris is about one degree below what it should be on my screen (1280/1024). But I believe what is getting me bad results on the longitude readings is that the sun is coming up and going down too soon for the area I'm in. I parked the sub right on the 15 degree line (using CTRL-click) and I still was getting a difference of about 51 minutes between my sun set and the GMT sun set reported on Van's almanac (instead of the expected 60 minutes).
I need to play around with it some more to see if I can find any consistency with the times so that I know if I should add a couple of degrees here and there to match the game map.
Thanks,
Ron
Congratulations for installing :D
The sunset times seem to be a good bit off. Better use the sunrise times. I think you already read it bould you also should use the red-light-off point as your local sunrise time.
All in all it seems like the real navigation is a bit inaccurate because it depends on many factors as time measurements, average speed calculations and estimated distances. And everything is influenced by the weather.
But it's still a fun way to play ;)
Kumando
07-04-07, 05:38 AM
I would really like to try this mod because i love manual navigation, i already navigate manual but with Dantenocs method but this one seems more interesting . The question is can you use the sextant at sunrise, noon and sunset or only at night with the stars? If its possible can someone make me a quick tutorial to learn it?
Thanks in advance.
Hi Kumando,
I THINK I read somewhere that you can shoot also the sun and moon with the sextant. I'm pretty sure I read that but don't know where. I tried it once just for fun but got nothing out of it and forgot about it. As you asked I will check again if it was in the manual that came with the mod.
divingbluefrog
07-04-07, 08:12 AM
Hi Herr Kaleun,
As you can see it, this is my first post here, nonetheless I'm an old player with a very personnal and heavy modded stock game.
I take the opportunity to tell my gratitude to all the modders and the people of this forum for the incredible amount of work they did.
If I never posted that's because I allways found the answers to my questions...:)
But....with this marvellous tool that is RealNav, for the first time I'm facing a problem I can't solve. To make it short : How do you know with precision (I mean to the degre at least) what is your current course heading?
The dials provided, especially the compass is far to rough for a fine reading. The only solution I managed to find is to use the free indoor cam to look closely at the compass behind the CO.
But it's not really playable, and not very precise.
Has anybody a solution?
Thanks
Hi Herr Kaleun,
As you can see it, this is my first post here, nonetheless I'm an old player with a very personnal and heavy modded stock game.
I take the opportunity to tell my gratitude to all the modders and the people of this forum for the incredible amount of work they did.
If I never posted that's because I allways found the answers to my questions...:)
But....with this marvellous tool that is RealNav, for the first time I'm facing a problem I can't solve. To make it short : How do you know with precision (I mean to the degre at least) what is your current course heading?
The dials provided, especially the compass is far to rough for a fine reading. The only solution I managed to find is to use the free indoor cam to look closely at the compass behind the CO.
But it's not really playable, and not very precise.
Has anybody a solution?
Thanks
Hi and welcome !
To answer your question shortly: Yes :)
What you are looking for is to be found here:
http://www.subsim.com/radioroom/showthread.php?t=109214&highlight=dials
:up:
Hope this helps. Be careful installing it though it introduces many changes to the menu_1024_768.ini.
Greetings, i.
orangewhale
07-04-07, 10:15 AM
I thought id post this here as this is a problem it seems related to the real nav mod/s albeit a small one. My recognition manual dissapears when i play sh3 only parts of it appear, why is this? it seemed to be okay until i installed real nav mod and the real nav fix which gets rid of the marker/guide which gives away your position, i think one or the other has caused this problem, but i want to play with both mods what do i do, hopefully im wrong and neither mod is causing the problem. HELP!!!
divingbluefrog
07-05-07, 05:06 AM
@ Ichso
Thanks for the answer. You put me in the right direction.
I managed to find the original mod by EX_Rasinban. But I'm not satisfied by the look of the compass. As you can see here :
http://ubootwaffe.net/u505/cr_hs.html
the compass used in U-boot was quite sober. I'm still working on an improved version.
@ Ichso
Thanks for the answer. You put me in the right direction.
I managed to find the original mod by EX_Rasinban. But I'm not satisfied by the look of the compass. As you can see here :
http://ubootwaffe.net/u505/cr_hs.html
the compass used in U-boot was quite sober. I'm still working on an improved version.
This would be great. I never really cared yet since the compass in this mod looks very sweet.
I thought id post this here as this is a problem it seems related to the real nav mod/s albeit a small one. My recognition manual dissapears when i play sh3 only parts of it appear, why is this? it seemed to be okay until i installed real nav mod and the real nav fix which gets rid of the marker/guide which gives away your position, i think one or the other has caused this problem, but i want to play with both mods what do i do, hopefully im wrong and neither mod is causing the problem. HELP!!!
I never installed the RealNavFix but still without it I see no tails at the map contacts. Perhaps you installed the wrong version of RealNav ? E.g. an older one that isn't compatible to GWX ?
divingbluefrog
07-05-07, 09:34 AM
So DUMB we are!
Did you ever wonder what was the purpose of the dashed, zoom sensitive, lines on the borders of the map?
We have it right in the front of our noses and never got it....
So.....NO!?....Really?!.....Meridiens and Parallels of course!
You don't believe me? Just go to the cross point between the AN26-AN21's limit and the Greenwich meridien. Yes, you are on the 60 N and 0 W point.
You can find another references as well : vetical limit between AM and AN grids on their north part fit the 5 W....and so on.
So now you can draw your own parallel and meridien lines everywhere in the world!...Nice, isn't it...:) And with the most precision due to the level of zoom you choose.
Another tip : After having set a course heading, wait a little to be sure you are on the straight line and then hit rudder amidship. This should help the helmsman to stay alert during the course.
Did you ever wonder what was the purpose of the dashed, zoom sensitive, lines on the borders of the map?
We have it right in the front of our noses and never got it....
So.....NO!?....Really?!.....Meridiens and Parallels of course!
buahahahhaa :rotfl:
yeah, I want comment on this one
btw I've tried rudder amid and didn't do anything to keep course...
divingbluefrog
07-07-07, 09:59 AM
Well, it's done, for the most part.
I have now a fully functional compass, with + 0.5deg precision.
http://img131.imageshack.us/img131/5593/compasseo3.th.jpg (http://img131.imageshack.us/my.php?image=compasseo3.jpg)
Taken just after out of the pen in Bergen.
As an help, I put a listing of the meridiens and parallels' scales in the map window.
http://img131.imageshack.us/img131/2951/scaleslistsz5.jpg
If you don't mind editing your menu_1024_768.cfg, you could move the block given by Kaleun Freddie for the sextant to the G34 group (you'll need to change the ParentID for that of the group) and then, the sextant will be only available in exterior view, as it should be, IMO.
Im also thinking of having an access to the SS/SR chart in game, but I don't know if I could succed in such a try....:hmm:
What does that little notepad on the last picture show ? Shows it the latitude and longitude under the cursor position ? That would be great to make some more precise drawings on the map for real navigation.
divingbluefrog
07-07-07, 01:38 PM
No, it doesn't. It's just a memo that tells you what is the scale of the meridien tab at the current zoom : here 50km so 05' per dash.
I think Kaleun Freddie was to hard cutting the zoom levels. I find that if you only cut the three first, you still get a 2500m zoom which gives you a 15" resolution, whithout showing you the position of your sub. That's how I find that the exaction longitude of Bergen is 8 18' 45" E (entry of the pens).
I also managed to include the SR/SS chart in game, but as free sheets, one page per month, and not as a book which was my first thought. After all "do it simple"...:)
Great but while playing in 1680x1050 the dashed map outline is ... softened (gradient) so it not even near precise anyhow.
Verdammt...
I'll give a look if it's possible to turn off going off course in schwere wesser.
divingbluefrog
07-07-07, 07:37 PM
It should be.... but I'm still investigating this field and I'm in the fog....an heavy one....
But I've good hope that someone will find the solution. Weather does not alter the course when playing assisted mode. Now we do exactly the same thing, give an initial heading and let her go....
A waypoint, in a way or another, force the sub to go exactly on it, but we know now that the wind's speed and direction influence the course, it means that the program make constant correction of the bearing.
It's not a matter of variating speed, if so, we should keep the bearing, but have a error on the ETA. In assisted mode, the ETA changes when the weather changes.
I'm just beginning a new set of tests and I hope that I will have a clearer sight at the end....
divingbluefrog
07-08-07, 07:56 AM
Hum, I have a good and a bad news.
The good one is that the drift problem in heavy weather is solved, the bad one is that there is no problem.
I suspected the truth since the beginning but lack of a truthfully compass I couldn't verify it. Now it's done. Our Elite helmsman do their job and they do it well. Drift in heavy weather is a reality, as anyone with a sailing experience could tell you. And the model provided in the game is more or less accurate, rather more than less IIRC my past experiences at sea.
I will not give all the details about the tests I made, but to sum up :
- your average speed rise when the wind blows from behind and vice versa, in respect to the lost of speed due to the surging sea.
- you drift in the direction of the wind, and the drift is proportional to the wind speed.
We wanted realism in the sim, we get it...:)
The dev made only one little error which will save our lives. The compass give you your true heading, not the initial one. Of, course, you aren't obliged to read your compass after a long ride in rough water...:)
For the speed variation, no other means that your best estimation.
Good hunt, fellow Kaleuns.
The dev made only one little error which will save our lives. The compass give you your true heading, not the initial one. Of, course, you aren't obliged to read your compass after a long ride in rough water...:)
For the speed variation, no other means that your best estimation.
Yeah the sim might be correct but still we need constant adjustment to our course. For me it should be that way. Helmsman corrects all the time to keep us on 0° course and after 500km we end up still heading 0° but we're 20km SW from our estimated end point because of drift, wind slowing us down etc.
In a very heavy weather I let them go, hit the TC and watched. We end up heading 60° of given course... probably we would be doing circles soon...
divingbluefrog
07-08-07, 04:53 PM
It's not really surprising... Imagine that, you are caught in a storm, not the most terrific one, but a serious, wind speed 15m/s which is equal to a 10 in Beaufort scale, with a surg of 7-8 m. And you have to keep the course on, say, 0°... but the wind is blowing straight port, and so is the surg direction. The ship will easily show a helms compass moving from 355 to 05, and you will try to keep it in the average position.
Your speed is slow, 7-8 Knts, with sudden acceleration and short braking when the fore hit the wave, the ship isn't really well responding to the helms.
This is modeled in the game by a 1-2° drift per hour for an average distance of 31-32 km, which seems very close to the reallity. I don't think that high TC (I mean 256<, never play above) have any influence on that. But for sure if you let her go for 15 or 20 hours in a raw whitout giving any corrections, you can easily be out of course for 30-40°.
Major rule for the RealNav navigator : in a storm, stay on the bridge, or you will get lost.
The thing is that noone says the subs behaviour under stormy conditions is unrealistic. It's just tiring to play sometimes if you have to click on the compass every 2 seconds under 128x TC.
Imagine that if you want to travel over to NY and the storm wouldn't end for 1-2 weeks.
That's where it isn't fun to play anymore so we would like to give the task of keeping course trustfully in the hands of our helmsmen :)
divingbluefrog
07-09-07, 08:10 AM
But you can as the compass give you your true heading. It's just a matter to make one correction point every day.
If you travel to NY, roughly, you will get a 270° heading. After the first day of storm, you find a 260° heading. Well, you spot your new estimated position. You set a new course to, say, 280°. 24H later you find a 282° true heading. New correction and so on.
I know that the compass gives the correct absolute heading of your sub. But the matter cannot be solved that easily by correcting the course once a day because of the thing that Hadrys said sometimes he got off course by 60° (I assume he meant in far less than a day).
Also if you correct an error of 10° in your course by 10° in the opposite direction you want to travel you produce even more error because the course changes slightly over time and not abrupt all at once. But I don't know how big this error would be in the last case this might be the smallest problem overall.
I know that the compass gives the correct absolute heading of your sub. But the matter cannot be solved that easily by correcting the course once a day because of the thing that Hadrys said sometimes he got off course by 60° (I assume he meant in far less than a day).
Also if you correct an error of 10° in your course by 10° in the opposite direction you want to travel you produce even more error because the course changes slightly over time and not abrupt all at once. But I don't know how big this error would be in the last case this might be the smallest problem overall.
It was a f..in storm of the year, I've hit TCx256 and watched how the compass turns on my eyes like in roulette...
Problems produce problems. If we assume a correction once a day that would be: we are +10 so for the next day go -20. But under condition that speed, sea state etc are the same. So the only way to navigate properly in heavy weather is to constantly click the compass. I can see that when allowing up to 3-5° divergence in 128 (256max) and than clicking -3-5° should give a nice accuracy but this is insane when you need to go 5000km even in a straight line!!! Add up to this plane attacks after max 2hrs on the surface (maybe 4 during night above 60°N which isn't that dark...).
I really don't know in which RealNav thread to write, there are at least 3 big ones of them.
I have a little suggestion as I made a little mistake while playing yesterday:
I accidently deleted all my drawings on the nav map with the stupid delete-all button (which doesn't even ask if you REALLY want to erase EVERYTHING :shifty:).
In the ...\data\Menu\*_menu.txt files are the functions of these buttons listed, I commented out the ones which refer to the everything-eraser. To be sure I did that in the de_menu.txt and the en_menu.txt although just the de_... should be used in my case.
Didn't test it yet, will do it later.
Did you erase your entirecourse plottings from weeks of patrolling accidently ? This is really frustrating. I don't want to redraw it from my written log book either.
Uber Gruber
07-12-07, 08:10 AM
I'm also a little confused by the three RealNav threads. I'm trying to get my head around Real Navigation, even bought a book on Astronomy to try and figure it all out but it's a tad confusing to say the least.
Could someone list the basic steps required to determine my boats position ? I can then trawl through stuff in these thread and online to put together a detailed process of steps to use in SH3.
I don't think we can expect people to play only in real time and clicking the compas dial every couple of secs in storms is also a pain so perhapps we should just accept that storms will throw out our calcs, at least until there's a break in the sky to get a decent celestial fix and then make compensating course changes. Would this work ?
I'm thinking of Worsley's epic navigational feat in the James Caird with Shacklton and Crean between Elephant Island and Prince Hakkon Bay, South Georgia. Worsley could only make a couple of sun shots during this 800mile crossing yet still managed to find South Georgia, an Island which is effectively a needle in a haystack in the South Atlantic.
Surely it must be possible to successfully navigate our boats with the Sextant mod, some tables and course compensation ?
I admit I may be over simplifying things as I'm still TRYING to get my head around all this, having never learnt navigation prior to following these RealNav threads.
Thanks....
Ok.
The description from the manual of how to use the sextant is pretty useable. The manual that came with the mod.
When at the northern hemisphere wait for something around midnight, this can make finding Polaris a bit easier.
The sextant is best used from the f10-deck gun view as this is much better stabilized than the brigde view.
Align the sextant scale with the bottom and top of your screen as it is shown on the screenshots in the manual or somewhere early in this thread.
Then just take the reading of Polaris' height above the horizon.
If you are new to this mod you should first attempt to get your latitude by this method and then compare it to your real postition.
For me it worked very well to use the course plotting tool. With
RealNavMod installed this wouldn't let me actually plot a course but shows me my exact position.
By cheating this knowledge you can get more used to the mod.
Measuring longitudes is simply a matter of measuring the time difference between your local time and GMT. GMT is the time displayed in the rightmost down corner of the screen, with the white background.
Getting the local time is done by waiting for the sunrise and comparing that time's difference to the value of Van's SR/SS almanac that came with the mod too.
Let's say you measured your latitude to be 54°N ad midnight. You kept this latitude by travelling 270° or 90°.
New you look in the almanac and search there for the table containg your specific time of the year.
From there you note down 2 values: the sunrise time for 50°N and the one for 60°N.
For example you're in Feb. 15th, the almanac states that SR time for 50°N is 7:12 a.m. and for 60°N it is 7:40 a.m.
Now you know that you are 4/10th between 50°N and 60°N (assumed above).
So you interpolate the SR time for 54°N, this would be:
0.4 * |7:40 - 7:12| + 7:12 = ~7:23 a.m.
This time you note down.
Now you wait for the sun to rise. We experienced that the most exact moment (in terms of this game) is the moment when the redlight gets turned off.
Exactly at this moment you write down the GMT shown in the right down corner.
Now you know that your local time is 7:23 because that's the SR time for your 54°N latitude and you can calculate the difference to GMT.
Let's say your GMT clock showed 8:35 when the redlight got turned off. This means you are 1:12 behind GMT. Every 15° longitude (west or east) mean one hour time difference. So by 1:12 hours (behind GMT) you get a longitude of:
12/60 = 0.2 => 1:12 = 1.2h => 1.2*15 = 18°W longitude.
Hope that wasn't confusing at all :roll: :sunny:
Uber Gruber
07-12-07, 09:38 AM
@ichso
Hope that wasn't confusing at all
Confusing?!!! My god man that's the most clearest explanation i've read on the entire subject!!!! Thankyou immensely.:yep:
I was getting there but started getting confused by some of the posts regarding the second clock above the GMT clock. Some say its local time but gets screwed passing GMT and some say it updates half way between longitudes. I say...HELP!
Just a couple more questions if possible:
1) Is it possible to get lattitude readings by sun spotting using the sextant ? If so then a combination of both Sun and Polaris spotting should increase my position fix accuracy.
3) I should be able to fairly accurately track my course between fixes using distance = speed * time ?
2) In fine weather and calm sea states i should be able to navigate away from a known lattitude (other than heading 90 or 270) before knowing my longitude and still obtain a fix on my position by doing the maths ?
4) In rough sea states I should expect to end up off my intended course due to drift. The ammount proportional to the duration and severity of the rough weather ?
5) If SH3 allows sun spotting then I should be able to correct my position fix by shooting the sun in cloud breaks during a storm...if any ?
6) Is it really necessary to force the helmsman to maintain course during storms and high time compression by constantly clicking on the compass ?
7) What is the max time compression i can use in order to stay within a healthy margin of positional error and why ? (I have also read that the clock goes a bit wobbly during high TC).
Thats it, and once again I really do thankyou for taking the time to answer these probably very obvious questions
:up:
:D
This is only obvious if you already know the answers ;)
As you ask this sun-shooting with the sextant I get interested in this again, didn't manage to do this right yet either. But I just learned on wikipedia that many captains got blind on one eye by looking into the sun with a sextant :know:
It should work if the sun is at it's zenith, that would also give away your current longitude as you know your local time would be 12:00 at this moment.
But I don't know any practical way to see if the sun is at it's highest point in SH3.
Perhaps wait til nearly noon and then just stare into the sun for a while under 32x TC ? :hmm: Have to try that.
And hopefully won't have to wear an :arrgh!: (no, not a hat) after that.
I should be able to fairly accurately track my course between fixes using distance = speed * time ? :yep:
Just a little hint, I even don't use myself very often:
The line drawing function gives away slightly wrong values as which the current drawn line is.
More precise is the combination of the scale of the map and the use of MooseMeasure:
http://cip.uni-trier.de/~schmidt/sh3/LineExt.tga (http://cip.uni-trier.de/%7Eschmidt/sh3/LineExt.tga)
(goes to ...\data\Menu\MouseCurs\)
(a precise plotting tool, don't be shocked about it's visual size though ;) )
You can of course plot your course really precise, especially if you do it with minute-precision. I think I've got too lazy to do it THAT exactly though and it still works out in the end.
If you got in some attack at an convoy or get chased by DD's you won't know your exact position afterwards anyway.
6) Is it really necessary to force the helmsman to maintain course during storms and high time compression by constantly clicking on the compass ?
7) What is the max time compression i can use in order to stay within a healthy margin of positional error and why ? (I have also read that the clock goes a bit wobbly during high TC).
This is still odd. We found no way to make the helmsman keep exact course yet so it's still clicking the compass like crazy under higher TC and in bad weather conditions.
The error in the set course seems to be not that easily predictable either. It's not to be calculated out of wind speed and direction + own course. That's too bad.
Also, sometimes I felt like going under 512x didn't produce a drift as high as when using 128x or 256x. But some other times it really didn't matter.
You can even course errors out by 'over-correcting' it when it got wrong, it's a matter of experience though.
And in the end it's not even that bad or unrealistic to be some few degrees off course. At least you don't just spawn here, race there, this was a bit too easy in the long run :arrgh!:
Uber Gruber
07-12-07, 10:38 AM
Excellent posts, pretty much sum up the state of play re Real Navigation....and thanks for the Moose Measure, I quite like it to be honest. I've had my fun being a captain, so now I want to try my hand at the being the navigator. I also imagine shadowing targeting convoy's via Hitman's research will add to this.
I don't mind being a little uncertain of my position, uncertainty is good and realistic, just wanted to make sure I wouldn't be really off course.
I'll start putting all this into practice over the weekend....thanks mate:up:
No problem ;)
Now we have another pair of eyes looking for flaws with this mod and their solutions, so keep posting what you find out :yep:
divingbluefrog
07-13-07, 04:25 AM
Hi,
There is something still confusing me. From different sources, I find that Polaris true declination is betwwen 89°15' and 89°45'N (today).
This declination is time (years) relative. But does the game take in account the true position in years 39-45 or is Polaris right on true North?
BTW I use a 40' correction, giving the Dev Team credit for accuracy, which give me good results. The point is that I use it as a positive value, not a negative as Van suggests in the manual. Seems logical to me that if true North is above Polaris position, correction must be positive.
Hi,
There is something still confusing me. From different sources, I find that Polaris true declination is betwwen 89°15' and 89°45'N (today).
This declination is time (years) relative. But does the game take in account the true position in years 39-45 or is Polaris right on true North?
BTW I use a 40' correction, giving the Dev Team credit for accuracy, which give me good results. The point is that I use it as a positive value, not a negative as Van suggests in the manual. Seems logical to me that if true North is above Polaris position, correction must be positive.
Hi,
I just used the 1° difference yet, as stated in the manual.
Everything I read in the internet about this says that Polaris stays within 1°(or sometimes 2°, 0,5°) difference to the North Pole, but not if it is above or below it.
But researching this I found something interesting:
http://www.synapses.co.uk/astro/bearings.html
Right in the middle of the page starts a section on how to measure the local time by watching the stars. If this works in the game too this could lead to a powerful alternative to the (sometimes odd) sunrise/sunset method.
I definitely have to try that the next time I play.
PS@divingbluefrog: Could you post your sources for Polaris' position at a specific date if you read it in the internet ?
divingbluefrog
07-13-07, 04:23 PM
Well, I confirm that Polaris declination today is 89°15' :
http://en.wikipedia.org/wiki/Pole_Star
Should be inferior in 39-45 as it is currently increasing its declination.
And, AFAIK, true North is true North, nothing can be "above" it.
Is this normal or did some mod this ?
http://cip.uni-trier.de/%7Eschmidt/sh3/suw.JPG
don1reed
07-18-07, 06:55 AM
:hmm: ... one thing for sure, it's exactly either SR or SS at your location. (time tells me probably SS)
Are your using NYGM or GWX in conjuction with RN?
GWX 1.03.
Either I don't remember it or I have never seen the sun *behind* the see. This is strange.
The time shown there would more or less fit with the one calculated from Van's SR/SS almanac though. And that is strange too as the SR/SS time was the moment when the sun sticked exactly half out of the water before.
This is the first patrol where such things occur. I even haven't installed any new mods.
don1reed
07-18-07, 08:49 AM
sri, ichso, I don't have a clue. I just had to do a complete, new, install of sh3/1.4 and both gwx & nygm mods as realnav really started hosing up the sh3 for me on my machine. I'm sort of leary of trying it again for fear of glitch problems the combo creates on my rig. (oil & water ... all I need now is a lil vinegar ;) )
This mod is creeping me out. Since my newest patrol started everything with the sun's movement and position works fine again.
The whole engine seems to be capable to simulate real navigation but was never ment to. This is why such problems occur from time to time.
@don1reed: Sry to hear that ;). I hadn't to do any further SH3 installations since GWX. Perhaps just lucky ? :hmm: :D
I've made my rather final mods compilation (trying yet to remove some and see the effect) but I've incorporated a sextant. An improved ver by can't remember who ;) but it's very good looking ;)
I'm also messing with weather settings, now gonna try interval=1, rnd fog and clouds and if weather is not that bad maybe some manual plotting?
I don't understand how realnav influences game performance?
I don't understand how realnav influences game performance?
It doesn't. Why do you ask ? :roll:
I've made my rather final mods compilation (trying yet to remove some and see the effect) but I've incorporated a sextant. An improved ver by can't remember who ;) but it's very good looking ;)
Is that available somewhere around here ?
Otherwise: is it big ? Can you send ? :D:oops:
> It doesn't. Why do you ask ? :roll:
donreed> as realnav really started hosing up the sh3 for me on my machine. I'm sort of leary of trying it again for fear of glitch problems the combo creates on my rig.
:huh:
> Is that available somewhere around here ?
> Otherwise: is it big ? Can you send ? :D:oops:[/QUOTE]
as usual don't have a clue where I got it... just two days ago I've deleted the readme?
http://mrhadrys.com/silenthunter/Sextant.tga 70kb
Thank you.
This sextant looks real stylish. And teh background seems finally to be real transparent ;). :up:
don1reed
07-20-07, 03:08 PM
As far as sextants go...do you think something like this possible?
http://i77.photobucket.com/albums/j42/donhreed/splitimage.jpg
The cream on top would be a read out of the angle of the body. I always thought using the obs scope would be a great candidate for conversion into a sextant. Of course, a split view would be necessary to get horizon and body together.
Hm. What do you mean ? Sry if I miss something obvious there :oops:
don1reed
07-20-07, 03:15 PM
The red circle view is what mariners actually see when using a sextant. Do you suppose it's possible that the obs scope be made into a sextant?
and be able to display the actual angle the body is above the horizon with a split image to get both body & horizon into the view finder?
The red circle view is what mariners actually see when using a sextant. Do you suppose it's possible that the obs scope be made into a sextant?
and be able to display the actual angle the body is above the horizon with a split image to get both body & horizon into the view finder?
The scope's scale should be not too hard to edit so that you can make star or sun readings quickly with it.
The thing with the split image I don't know though. What the modders did so far is to put some additional static images into the game, like those tables on the nav map. Or the FavDialsMod uses some certain script functions to print things onto the big (sliding dials) which gets printed onto the 3D models of the dials and gauges.
But maybe it's not possible to puzzle such screen data of the very dynamic exterior view together to get a split image like you mentioned.
don1reed
07-20-07, 04:35 PM
Re split image:
The horizon mirror on a real sextant of the 39-45 vintage was 1/2 clear glass and 1/2 mirror in order to see the horizon and the reflection of the body simultaneously when the index arm & mirror was rotated after capturing the body and bringing it down congruant with the horizon.
The #2 scope aka Attack scope in SH4 has a split image function used to determine distance of the target ship...I just thought some interprizing, gifted, modder might be able to swing it....wishful thinking on my part.:yep:
this is my first post :up:
OK I think i have finally cracked the shiii :sunny: problem.
I have written a sun calculator for real nav that is more accurate than the sun tables that are supplied with real nav. I dont know how to upload information to the internet so if someone can give me some info ...would be great.
Now I havent worked out the star problem yet(next project;) ) but with my calculator you can at least navigate successfully during the day.
it goes like this:
before sun gets up read polaris 41 degrees
read Dubne 69.5 degrees.
-90-41+89=42N
90-69.5-62=41.5N
ok close enough lets use polaris...entering 42 degrees into my suncalc:
1/1/38 SR 7:30 SS 16:36 Declination 22 50 Equation of Time 3.4mins
we can now approximate noon at:
16:36-7:30=9:06 / 2 = 4:33+7:30 = 12:03.(just for reference)
Sunrise actual 7:22
7:30-7:22 = 8minsx60=480seconds / 4secs per arcminute = 120' east of our meridian. time difference on the clocks is 5hrs.
7:22-2:22 = 5hrsx15 = 75 degrees - (120'/60=2degrees) = 73 W
Noon actual = 11:58 suns altitude = 28 degrees.
our latitude by suns reckoning:
90 degrees - altitude + Suns Declination*
looking north add declination
looking south subtract declination
90-28=62-22.5= Lat:39.5 degrees
now for longitude:
GMT=16:58(see notes on GMT below)
Greenwich apparent time = 16:58 - 3mins(EOT)= 16:55 (I rounded it, probably shouldnt for accuracy)
larger number on top
16:55
-11:58 = 4:57 4x60=240+57=297minutes / 4m per degree = 74 15' W
notes for GMT:
the time in the lower right(in the box) is your local time. the time in white that says "local time" below the date, is actually what local time would be if gmt was the time in the box. think about that for a minute. hehe. so for above..box time was 11:58 and white time was 06:58 so GMTime we ADD the time difference.
ok moving on..
Sunset actual 16:36 exactly 5 hrs west = 75 W
Summary:
Sunrise 42N 73W
Noon 39.5N 74W
Sunset 42N 75W
---------------------
average 40.5N 74W
actual lat/lon for new york harbour = 40 42'N, 74 02'W
so as you can see the more readings you take the more accurate you become, but any one of these readings puts you within 1 degree of your true position.(and actually more precise measurements (accurate star readings) and (3mins EOT instead of 3.4) would have put us closer than 1 degree.
I actually use a modified observation scope with degree markings to take sun readings at noon because my scope can elevate to 90 degrees.(that sun is too bright otherwise)
with this calculator you no longer need 12 or more pages of charts and tables. only a pencil and paper.:D
Kunsa.
Edit:found filefront so will get some files together, upload and paste a link here soon
p.s. I noticed some people didnt like the thickness of the latitude/;longitude lines on the map. I have solved this as my lat/lon lines are on the lowest 3 zooms(2500km and up) only
and seems to work out quite well. will post that mod too.
thinking about creating a navigation course plotter/finder not sure if it will be that useful.
Edit2:Sppppelling
Ive just realized why i was off by 1 degree in my previous post.
its because we assumed our latitude position was 42 degrees and used the sunrise/set times for that latitude in actual fact our latitude turned out to be 40.5 north, so if we had used that latitude our calculations would have been correct.
this means that it was a problem with measuring the star, but the sun calculator was exact.
http://hosted.filefront.com/Kunsa/RealNavAdditions.7z
feedback would be great.
don1reed
08-12-07, 01:05 PM
...Well, I've been away from this thread for a bit, but in the time away, I've been looking at other SIMS. One in particular that caught my eye was, Virtual Sailor vs.7.
Here's a pic of the virtual sextant within that simulation. It works 100%, btw.
It has adjustable shades to block the brightness of the sun.
It will zoom. in/out.
It allows the sailor to bring the heavenly body UL or LL to the horizon.
It measures the angle of altitude in both degrees and 4 digit decimal.
It gives the time in GMT Hr:Min:Sec and 4 digit decimal.
http://i77.photobucket.com/albums/j42/donhreed/v7sextant1.jpg
This is what we need for SH3 & 4.
With VS7, I am presently aboard a Type XXI in the middle of the Atlantic in early 1945.
http://i77.photobucket.com/albums/j42/donhreed/xxi.jpg
Virtual Sailor is located: http://www.hangsim.com/vs/
Cheers,
I will try the demo. I always wanted a sim where you can actually set sails :)
Too bad it's not for free though.
I will try the demo. I always wanted a sim where you can actually set sails :)
Too bad it's not for free though.
[code]
Hello! It could not be kept. I have the certificate " the captain of a yacht-steering 3 classes. " But last years had no opportunity to go under sails. But had a lot of pleasure with SH3. Very similar on the present float. The present trial for the seaman. Especially when has appeared mod Real Navigation. Many thanks to authors for pleasure. But to find a meridian of a place - on former a problem. In Virtual Sailor sails behave correctly, when a rate "Beidewind" (when the wind goes to sails in front and a little with a side), or "Galfwind" (the wind goes to sails to perpendicularly case of a yacht). (Excuse. I do not know as it sounds in English). Certainly actually with the present sails of work it is much more. On other basic rates in Virtual Sailor ("fordewind" and "Backshtag") the yacht behaves not so. But all equally is very funny.
don1reed
08-14-07, 04:28 PM
Hello Poul!
Yes, I believe I know what you mean. When sailing into the wind, in English it is called, sailing close-hauled. When sailing across the wind, its called "reaching", as in a broad reach, or beam reach.
Good to have you aboard and good luck with your profession.
Cheers,
Hello Poul!
Yes, I believe I know what you mean. When sailing into the wind, in English it is called, sailing close-hauled. When sailing across the wind, its called "reaching", as in a broad reach, or beam reach.
Good to have you aboard and good luck with your profession.
Cheers,
Right. These where the words :up: I knew I've seen them somewhere, must have been Sid Meier's Pirates :hmm:
Hello Poul!
Yes, I believe I know what you mean. When sailing into the wind, in English it is called, sailing close-hauled. When sailing across the wind, its called "reaching", as in a broad reach, or beam reach.
Good to have you aboard and good luck with your profession.
Cheers,
Yes. It that I wished to tell. Thanks. And how in " Virtual Sailor " has got U-Boot-XXI? In my program it is not present.
Look at http://www.virtual-sailor.net/. There many new models for the game, I found something 'The U-Boat' there, but it's a rebuild of a VII.
Some more googleing for "virtual sailor XXI" gave me the offical addon page of this game, there you find it among many other submarines.
@don1reed: Do you own this game ? I saw that it costs only 27$. Just tried out the demo version which ends after a few minutes of playing. Diving around in the mini uboat was fun ;) (cockpit view is nice).
Are there any interesting tasks in the full version ? Or is it just sailing around for fun ?
The FAQ states nothing about this, if I didn't miss anything.
EDIT: Look what I found:
This is a picture I've taken by myself a year ago or something in the vicinity of the Netherlands:
http://cip.uni-trier.de/~schmidt/Afb069.jpg (http://cip.uni-trier.de/%7Eschmidt/Afb069.jpg)
And THIS I found at the addon page of vs7:
http://www.hangsim.com/vs/images/downshots/botter.jpg
So, tell me, what kind of freakish coincidence is this ? XD
don1reed
08-15-07, 07:14 AM
:up: Ischo, that pic is SOOOO damn neat!
Yep, I bought the sim. But....
I'm afraid to announce that the virtual sextant is not connected to real world navigation. The celestial globe is tilted about one or two degrees, god knows which direction, which causes bodies to have the wrong altitude for date/time...so, you'll be constantly adjusting the angle of elevation and/or GMT.
As a virtual navigation community, we are sooooo tantalizing close to getting it right I can almost taste it!
The celestial canopy in vs7 is very close to real but not near accurate enough to make fixes to attach courses to. It is, however, much more accurate than SH3 or 4.
Again...great pic.
:up: Ischo, that pic is SOOOO damn neat!
Believe it or not, it was taken with my mobile, and that's not even a very special one, some standart, 2 years old Nokia model. ;)
Before I spend any money on this I have to play the demo with some downloaded ships first. I don't see the big point in JUST sailing around
I don't know if there are any special locations to visit or special things to do.
But the pure sailing and navigating sounds a bit like fun, I must say :hmm:
And there are really beautiful models available, too.
For the navigation issue though, I slowly get the feeling that we have to create our own game because all other ones just don't concentrate on that point enough :D
don1reed
08-15-07, 10:50 AM
Well, that phonecam is a keeper. Nicely done.
For the navigation issue though, I slowly get the feeling that we have to create our own game because all other ones just don't concentrate on that point enough
I agree :yep:
However, this morning using vs7, I put myself near Gibraltar on 21.3.2007 04:10:41 GMT (date of vernal equinox this year) took a sight of polaris and by using Height of Eye 14 feet for DIP correction and Index Correction (IC) of 5.9 moa, and also discovered that the GMT clock was/is 0:37:11 fast. After making the corrections I was right on the money!!!!!!! The line of position was lying right across my boat...he he...and just missed hitting me in the head!!!!!
I made sure I used the equinox to eliminate the seasonal tilt of the earth just to see how far or close I could come...the sextant corrections are very real and emulate life to the "T".
Have a great day.
This game is so neat. I think I just fell in love with the Mini Sub. You can actually drive it like a car, at least compared to a U-Boat ;).
I didn't try out the navigation issues yet. The games offers you full GPS support, even on the crappiest shooner from around 1700 :D.
The game only shouldn't be so childish and quit every few minutes because it's just a demo version :shifty:
don1reed
08-15-07, 02:05 PM
:D go ahead, cough out the 27$. You've spent alot more dining out with the mrs.:up:
This game is just the pure evil.
I've not done much else in my spare time the last 2 days than playing it.
The mrs is not amused :oops:
ryanwigginton
02-17-08, 12:58 AM
Seems no-one posted here for a while and so I'll ask... GWX2.0 compatible?
msalama
02-17-08, 10:07 AM
Yup, would like to know this as well if you don't mind ladies and gents :)
Tripitaka
12-30-10, 02:17 AM
[QUOTE=divingbluefrog;584804]So DUMB we are!
Did you ever wonder what was the purpose of the dashed, zoom sensitive, lines on the borders of the map?
We have it right in the front of our noses and never got it....
So.....NO!?....Really?!.....Meridiens and Parallels of course!
BlueFrog is correct. From my own obs I found that the heavy Green line crossing the GMT above Brighton is 51 degrees N. Also the 1st vertical line East of GMT is 1 degree East ( I live in kent) so therefore the black and white marks represent 1 Degree grad's at zoom level 0-500km.
I also discovered that the KM grid system has different size grids the closer and further you are from the equator. The grids thru the channel and across the Atlanic measure 180km (= 1d 30m) x 108km (= 0d 54m) I got this from noting that each mark is 120km in length
From this you can work out reasonably well your position in the 'real world' Just remember that degrees are sub-divided by base 6 = 10 minutes or 60 = 1 minute.
My current position (4th patrol) is 48 14 30 N 6 21 10 W :D
Who needs a sextant, hmmm? :cool:
Delareon
12-31-10, 02:05 AM
Ok im lazy :P
I dont want to go through the whole thread if somebody allready asked that question so i just ask with the risk that someone allready mentioned it:
This Mod is GWX 1.03 ready as allready satet. What about GWX 3.0?
I want to try it out with navigation but i dont want to change GWX Version ;)
vBulletin® v3.8.11, Copyright ©2000-2025, vBulletin Solutions Inc.