New Astronavigation Mod (ANM) – A Conception

[silent marshal]

First the disclaimer:
Meanwhile there a a few real navigation mods for SH5and they seem to work pretty well. I for myself dont know any of them in detail because I wanted to make my own ANM. If you should find out that I solved the issue in a way which already exists, please dont’t beat me.

Now what the ANM will do:
ANM is a mod for real navigation purpose. You determine your own position by using the „Höhendifferenzmethode“, which means that you have to gauge the hight of the sun twice a day by a sextant and then you can graphically determine your exact position at the nav-map by drawing the two „Standlinien“.

General set-up:
+ the position of your u-boat is unknown (no mark on the nav-map)
+ you have to use dead reckoning
+ you have to shoot the hight of the sun twice a day
+ you need to see the sun (no bad weather) to gauge its hight
+ you can use the „Nautisches Jahrbuch“ (nautical yearbook) to read some parameters you will need for your calculation as you would do in real wordl (with porper entries for each minute of the war)
+ you can choose an easy way to find the solution (if you get rid of manual calculations)
+ your navigation officer can make all the work for you and you will get your position at the notepad (this method will even use the Höhendifferenzmethode but is more exact because the calculation is done with the exact values – no user input needed; but you have to see the sun also twice a day)
+ you can read your exakt position at the notepad if you are totally lost (GPS-function :D)

Lets make a testrun! Note that the shown values are all fictive, they make no sense, it’s only to show how it would work.

On the nav-map you can see the UI with the slide out bar at the right where there are buttons for manual calculation (use the sextant), automatic calculation done by the navigation officer and immediate position determination.

http://s14.directupload.net/images/120405/c2xm7jy5.jpg (http://www.directupload.net)

The green cogwheel shows you that the navigation officer had shoot one hight and is waiting for the second shot.

At the left side of the nav-map you see another pen especially for navigation markings. The mark differ from the default one because additional information ist printed on the map to help you with dead reckoning (Date, Time, speed, heading and maybe the position).

http://s1.directupload.net/images/120405/new24qgc.jpg (http://www.directupload.net)

By using buttons for automatic calcualtions you will read the position at the notepad.

http://s1.directupload.net/images/120405/j98rm7pu.jpg (http://www.directupload.net)

Now after some rainy days you will know your exact position. It is midmorning and the WO reports fine weather. Press the button for manual calculation and a new UI will appear (notice: only draft version!).

http://s7.directupload.net/images/120405/ytbrezn6.jpg (http://www.directupload.net)

In the center you see the optics of the sextant („Halbspiegel“). With the first index at the bottom you choose the degrees, the second one is for the minutes and the third one, the „Nonius“ is for the minute’s decimals.
Before you shoot the sun (bottom of the sun touches the horizont line), you have to toggle whether you want to fill out all the white boxes or only the hight of the sun „Gem. Sonnenwinkel“: „nur Sonnenwinkel manuell eingeben“ – „EIN“.
If you decide not to use the nautical yearbook („Nautisches Jahrbuch“), toggle „Tabellenwerte automatisch berechnen“ to „EIN“, the GrW/GHA and Deklination will be computed exactly.
If all inputs are done, you can memorise the Azimut Z and the Radialversatz u.

Repeat these steps a few hours later and draw the lines on the nav-map and correct the position with the Horizontalversatz w to transform to UTM (coordinates).

After the second shot your nav-map will look like this:

http://s1.directupload.net/images/120405/phw4xq4v.jpg (http://www.directupload.net)

The middle of the center is your estimated position („gegißte Position“) and Markierung 1 in the upper rigth sector is your exact position – pretty fun!

The accuracy depends on the precision of your shooted hight of the sun and other factors you have to read from the nautical yearbook and of course of the precision of default SH5 map tools.


How does it all work?
The idea is to determine the exact hight of the sun from the exact position (which is read from SH5 but you don’t know). Now, everytime you use the sextant, the visual hight of the sun in your optics is calibrated regardless the position of the sun of SH5. What you see is not the sun of SH5 but a dummy-sun (the right side of the optics is a fake, the left one is the true background of SH5). This will allow to use calculations as in real life.
The advantage is that this method is totally independent from the hight of the default sun and in future stages you can easily implement all the stars you wish to navigate with. For this stage the sun will be sufficient.

This is the theory so far. So, the big question is: are there some modders out there who can do all the programming stuff and help me with the UI? I have pretty no experience with this kind of modding so the realization of this mod totally depends on outer help. I am convinced that this mod would be an asset for SH5 and will make simming more interesting.

For this time it’s enough, I guess. If you have any questions I will answer with pleasure. Detailled information to how it works on demand.

Have a nice day! :salute:

[Sartoris]

I'm no modder, but I love the idea! I hope someone can help you out because I'd love to be able to use this in the game. :yeah:

[Vanilla]

Accorind to my measurments the sun does not follow a real-world pattern (or any sensible pattern for that sake) on the SH5 skies, you can see it for yourself using sextant from TDW UIs mod. This invalidates the whole sky height measurement process. More to that there is a strong possibility that the sun position is dependent on the screen resolution. Even if there is a pattern, I doubt it is possible to see the horizont and the sun simultaneously given the tools we have.

[silent marshal]

@ Vanilla: you're exactly right: SH5 doesn't reflect realistic sun behaviour. The process I use is totally independent from SH5 and that's why it works absolut correctly. There must only be a script which prevents the use of the sextant-UI at heavy weather when the sun can't be seen (or at night of course) - but this for realistic gameplay only.

The crucial point of the process ist this:
If you know your exact position, you can calculate the hight of the sun. I do this as the first step (using SH5's exact position data which the player doesn't know) and now you can calibrate your sextant's scala this way that the (dummy) sun touches the horizont with the exact angle - and this for every second of a year.

See the result below: delta [Pos] ist the distance from the exact position of SH5.

http://s14.directupload.net/images/120405/piz3f42p.jpg (http://www.directupload.net)

I make some tests and the results are awsome. Depending on the accuracy of your input data your graphically located position is in a radius of a few hundret meters (well only if I use the exact calculation values; for real life conditions the accuracy will be 1km up and more - like it is in real world navigation).


I forgot to upload the nautical yearbook which will be written by a routine for a 1-hour period depending on your data input on the sextant-UI.

http://s7.directupload.net/images/120405/ofnukggn.jpg (http://www.directupload.net)

Here only the period from Minute 00-30 is shown. There will be a second page with the second half of the hour. Still in progress.

It works pretty well, belief me!

[urfisch]

very interesting stuff!

:yeah:

[Vanilla]

Oh, I see now! Sorry for being dumb in the first place. That's a very interesting idea!

[don1reed]

Excellent work, silent marshal. Very much looking forward to try it out.

[tonschk]

Indeed :up: very intresting

[quink99]

As one who has done a bit of RW celestial navigation in both sailboats and aircraft this would be the ultimate in immersion, challenge, and fun.

My congratulations, Silent Marshal! It won't be easy but it will be worth the effort. Good luck!

[LemonA]

The mod should do this:
the more rolling of the boat in the swell the harder to get an accurate "reading" from the sextant.
Real sailors take 3 or more Sextant-shots at one session to minimize human errors and control their sextant-readings.

But i see in your concept this:
exact position = just bringing down the lower limb of the sun until it intersects with the horizon at two different times
+ doing some mathematical drawings


Actual what you see through a sextant for example at quit swell is more like this...
http://img.xrmb2.net/images/987245.jpeg



The GUI looks excellent.


What do you do here exactly?
http://img.xrmb2.net/images/730042.jpeg
Links for the "Höhendifferenzmethode"-method?


I would prefer a complete nautical almanac (pdf-book) instead of computer generated mini-tables for my current position.


Are you plan to calculate the arcdifference horizon <-> lowerlimb of sun at your own? Formulas? Example?

[silent marshal]

ROLLING OF THE BOAT:
The human errors are an important point: they mostly determine the accuracy of our calculated position. I am not sure how to consider the rolling of the boat because in the sextant GUI the left side of the mirror is the "real" background (comparable with the UZO view: up-down-up-down...) but the right side is only a picture which is moved along the vertical axes. I don't know how to deal with this issue. I for myself would be satisfied if it is possible to make the horizont steady, regardless the rolling of the boat.

BACKGROUND OF THE METHOD:
A good source to understand what the "Höhendifferenzmethode" is about: www.kowoma.de/gps/astronav/allg_methode_1.htm (http://www.kowoma.de/gps/astronav/allg_methode_1.htm) (german page). There you can also find some hints about the graphical solution. I will explain some special corrections for use with SH5 later on.

ALMANAC:
The problem with the complete almanac is that you have to consider every minute of a year. This is possible to do but a lot of work. The point is, you have to find your day, the hour and minute and then read the data you need for your calculations. So you have to dial these inputs correctly to avoid false user input (human error). With the dials at the GUI, this human error factor is factored in.
But it's possible to make a complete almanac for the years of war.

FORMULAS:
All values are calculated with formulas (hight of the sun etc.). This is essential to get the azimut (A) and the Radialversatz (u); without them you can't determine your position. Examples of the formulas will follow soon (it's a lot of stuff).

ACTUAL TASK:
At the moment I am working for the method how to factor in the moving of the boat from T=1 (first shot) to T=2 (second shot), which will be used more often. Some more mathematics to do...:yawn:

PS: I implemented only my sextant-buttons to the GUI of Dr.Jones. Hope it't ok for you, Dr. Jones...

[Captain73]

Bravo Marshal!!! To which interface will this mod??? Thanks for the reply!

[THE_MASK]

You can have a steady horizon looking thru the uzo by ticking the in game difficulty setting .

[HerrFritz]

Very interesting idea , sir! I'm waiting such a mod for years.May I ask you where from is that sextant interface and if is it functional ? I would like very much to try it.

[reaper7]

Outstanding. PM sent :up:.

[TheDarkWraith]

how are you making this pen add information to the nav map? And how are you getting this information (pen mark and additional info) to scroll with the nav map :hmmm:

[quink99]

ALMANAC:
The problem with the complete almanac is that you have to consider every minute of a year. This is possible to do but a lot of work. The point is, you have to find your day, the hour and minute and then read the data you need for your calculations. So you have to dial these inputs correctly to avoid false user input (human error). With the dials at the GUI, this human error factor is factored in.
But it's possible to make a complete almanac for the years of war.

FORMULAS:
All values are calculated with formulas (hight of the sun etc.). This is essential to get the azimut (A) and the Radialversatz (u); without them you can't determine your position. Examples of the formulas will follow soon (it's a lot of stuff).


If you haven't already found them, Silent Marshal, you may find these two links helpful.

Celestial navigation data for assumed position and time

http://aa.usno.navy.mil/data/docs/celnavtable.php (http://aa.usno.navy.mil/data/docs/celnavtable.php)

Navigation star finder

http://www.tecepe.com.br/cgi-win/cgiasvis.exe (http://www.tecepe.com.br/cgi-win/cgiasvis.exe)

Each will allow you to calculate the offered data for almost any date or time including our area of interest, 1939 thru 1945.

[DrJones]

Hey marshal, that is a very great idea...Look at PM

Best Regards

DrJones:salute:

[DrJones]

ROLLING OF THE BOAT:
The human errors are an important point: they mostly determine the accuracy of our calculated position. I am not sure how to consider the rolling of the boat because in the sextant GUI the left side of the mirror is the "real" background (comparable with the UZO view: up-down-up-down...) but the right side is only a picture which is moved along the vertical axes. I don't know how to deal with this issue. I for myself would be satisfied if it is possible to make the horizont steady, regardless the rolling of the boat.

BACKGROUND OF THE METHOD:
A good source to understand what the "Höhendifferenzmethode" is about: www.kowoma.de/gps/astronav/allg_methode_1.htm (http://www.kowoma.de/gps/astronav/allg_methode_1.htm) (german page). There you can also find some hints about the graphical solution. I will explain some special corrections for use with SH5 later on.

ALMANAC:
The problem with the complete almanac is that you have to consider every minute of a year. This is possible to do but a lot of work. The point is, you have to find your day, the hour and minute and then read the data you need for your calculations. So you have to dial these inputs correctly to avoid false user input (human error). With the dials at the GUI, this human error factor is factored in.
But it's possible to make a complete almanac for the years of war.

FORMULAS:
All values are calculated with formulas (hight of the sun etc.). This is essential to get the azimut (A) and the Radialversatz (u); without them you can't determine your position. Examples of the formulas will follow soon (it's a lot of stuff).

ACTUAL TASK:
At the moment I am working for the method how to factor in the moving of the boat from T=1 (first shot) to T=2 (second shot), which will be used more often. Some more mathematics to do...:yawn:

PS: I implemented only my sextant-buttons to the GUI of Dr.Jones. Hope it't ok for you, Dr. Jones...

Hey Marshal,

thats a great work you are doing here and you have my full support.

But don't forget, there will be an update which i will hopefully release here soon, when my workstation don't play any more cheats with me...

Best Regards

DrJones :salute::yeah:

[Sartoris]

I hope TDW will have time to coordinate his efforts with you so that this wonderful idea gets incorporated into NewUI. :up:

[silent marshal]

how are you making this pen add information to the nav map? And how are you getting this information (pen mark and additional info) to scroll with the nav map :hmmm:

This is exactly the problem: I don't know how. :D I have reflected what I would need and made some postworks with photoshop. To breathe life into these ideas I depend on experienced modders/programmers.

The calculation background is ready, now I am waiting to launch the next phase.

I assume that SH5 always knows the exact position of the boat. This is the most important information I need. The rest ist pure calculation.

[ETsd4]

It works pretty well, belief me!

Sorry to say that, but that's not true.
A "graphical solution" for finding the FIXposition depends on Length/distances and arcs. The SHunter-world has different distances and different arcs. THere is a mismatch between the varying mercator-projection of the real world and the constant mercator-projection of SHunter.
The only places where SHunter and the real-world is fairly equivalent is near the equatorial region (real world= 60nm, SHunter= 64.79nm). There will be never ever a "graphical solution" you will draw with SH5 map-tools which your picture implies here ... http://s1.directupload.net/images/120405/phw4xq4v.jpg

[silent marshal]

Sorry to say that, but that's not true.
A "graphical solution" for finding the FIXposition depends on Length/distances and arcs. The SHunter-world has different distances and different arcs. THere is a mismatch between the varying mercator-projection of the real world and the constant mercator-projection of SHunter.
The only places where SHunter and the real-world is fairly equivalent is near the equatorial region (real world= 60nm, SHunter= 64.79nm). There will be never ever a "graphical solution" you will draw with SH5 map-tools which your picture implies here ... http://s1.directupload.net/images/120405/phw4xq4v.jpg

Hello ETsd4!

Thank you for your critical comment. You figured out, what is the difficult part of the problem. It seems that SH5 uses some sort of UTM (Universal Transverse Mercator) coordinate system. That means, that the higer to the north or south you are, the mote distances (width only) are streched. You can check this when you compare distances from SH5 with the ones in google earth. (I know, you are firm with all this, but maybe there are some readers who aren't.) For simming this means that you are travelling a greater distance as you would do in real world.

I have factored in this fact and that's what the "Horizontalversatz" is doing: it corrects the sphere/plane geometry of the "Höhendifferenzmethode" to the UTM system.

How my method works:
The calculation bases on a spherical system. Because of the great distances, we can transform it to a plane system, where circles are lines - that's what you are doeing in real world also. I can do this at the nav-map but consider not the coordinates of default SH5. Now I have to transfer the intersection point - which is the exact position at the sphere - to UTM of SH5 and this is done with the "Horizontalversatz".

I will make some more tests but I wonder if there are any errors left.

Critical comments always welcome! If I am wrong, ashes to my head and I will submerge into the deep of www.:nope: If I am right, SH5 will be more exciting.

[don1reed]

Both SH3 and SH4 have MapFiles. In SH3 it's located:

C:/Documents/SH3/data/cfg/Careers/skipper's name/0/_____.Map

In SH4 it's located:

C:/Documents/SH4/date/cfg/SaveGames/00000000/SaveData.Map

There isn't a "Map File" for SH5. (That I know of.)

An amateur mathematician, Celestial Navigation Enthusiast and practicianer; not to mention, an all-around nice guy, Michael Jones, created a script file using Python and Stellarium to take the data from the SH4 Map file and convert the numbers found therein into Geo Coords. Numbers such as:
-1198199.13, 6006413.50,0.00

by dividing these numbers by 120000.

i.e., -1198199.13 / 120000 = -9.9848993. The (-) sign indicates West Longitude and South Latitude. The quocient then becomes: 9°59.1'W.

6006413.50 / 120000 = 50°3.21'N.

Everytime a "save" is done on your computer while playing, it auto-updates your true position on the game chart, even if your boat's icon is hidden.

Alas, SH5 does not have a MAP file that I know of.

And, of course, the Python/Stellarium method of celnav was used because the celestial canopies in SH3 and SH4 are not accurate, whereas, Stellarium's canopy is true.

Once Python obtained your true coordinates, it pulls up Stellarium and presents the correct celestial canopy you would be viewing if you were in fact, at that location. All that was left to do was to take of round of virtual sights of altitude and azimuths of selected bodies and have Nories, or HO Pubs 211, or 229, or 249 and almanac at hand to do the sight-reduction...five times per day, as in real life.

Then again, the next problem was the matter of the Mercator Projection Chart. None are true in the SH games. They're charts meant to fit the resolution of your display. So...forget Dead Reckoning as well.

When Navigators purchase charts from authorized chandlers, the charts they buy are printed to very precise specification and are miniature ratios of the real world, i.e., 1:1,000,000 scale. This is an extremely precise ratio, which means it is accurate to the length of one Toyota Prius to 1M Prius, or 1 nm to 1M nm, or 1cm to 1M cm, etc. One could say it's etched in stone. The chart in these games...not so much.

Edit: I'm looking forward to see this come about and wish you great success.

Cheers,

[Nico71]

After so many attempts to get real nav to work in SH by the community - with variing success - I'm inclined to give up on it. I did it successfully in FSX, with sextant, weather ships and whatnot. That being said, I really hope that you get this to work! That'd be really awesome! :yeah:

[Sartoris]

Sounds like there are some problems to overcome, but man, it would be so amazing if you could pull this off!:rock:

[silent marshal]

Hi folks!

I made some fine tuning with the calculation background (thank you for your critical comments!) and it seems that most of the problems are solved.

Two examples:

Exact Position SH5 (SP1): N 64,385° E 3,296°
Travelling at 135° 60km from T1 (first shot of the sun) to T2 (second shot).
Exact Position SH5 at T2 (SP2): N 64,032° E 3,664°
Gegißter Punkt (= estimated position G1): N 64,080° E 2,200°

By drawing the Exact Position at T2 I got (SP): N 64,025° E 03,65° (compare with SP2).

Second example:
SP1: N 33,247° W -17,253°
Travelling at 210° 40km
SP2: N 33,01886° W -17,465°
G1: N 33,75° W -16,75°
Graphical solution leads to SP: N 33,01° W -17,463°

There are still some things to check but the results seem to be ok. If you don't change your position from T1 to T2 (who doesn't?) the results are more accurate. Aberration is a result of drawing in plane geometry in spite of the curvature of the earth. The greater the distance between T1 and T2 is the greater the aberration would be (but it's not the only factor).
:salute:

[silent marshal]

How to find your own position – Part 1.

With the ANM-Algoritmus you will have three output options to find your position with graphically methods as tools provide at the nav-map:

(a) Find your position as in real life by drawing two „Standlinien“. It is the most complex option for the user because you have to draw a lot of angles, distances etc. You also have to consider transformations from WGS to UTM_120 (the coordinate system of SH5). You also have to be careful when using the algebraic signs. You will see, this is an option for the sophisticated navigators among us :D.
(b) Let the „Navigationsrechner“ :rock: do all the algebraic stuff for you and find your position with horizontal and vertical distances (cartesian coordinates). This is the arcade version…
Method (c) has the same background as (b) but for those who like using the triangle, the position can be found with polar coordinates.


Now I will show you how it all works when you are at sea. I will not show any interim results which will go beyond the scope of that post.

You are somwhere in the atlantic sea, approximately 200km NW of Ireland, but you don’t know exactly. It is the 5th of October 1938, 10:12:00 UT1. You fix your assumed position (G1) at 56°N / 11°W. Now take your Sextant and shoot the sun!

Input values 1st measurement
Date: 05.10.1938
Time (T1): 10:12:00
G1: 56,0°N / 11,0°W
Angle of sun h_b: 22,898° (in this example, we use precise values).

From SH5 we read our exact position: 56,5°N / -10,0°W. Now we have all we need for the calculation. Start the Navigationsrechner!

Results of 1st measurement: (take a look at the three options mentioned above)
(a) Azimut A: 141°; Radialversatz u: -5,8km
(b) W: ---,-km; V: ---,-km
(c) Azimut epsilon: ---°; Distance D: ---,-km

What’s that? No values for (b) and (c)? These values are a result of the whole procedure so you have to make another measurement at afternoon.

But in the meantime we can draw our first „Standlinie“ with the results of (a). We start with drawing the Radialversatz u with the circle.

http://s7.directupload.net/images/120416/er56v2ri.jpg (http://www.directupload.net)

Now we draw the Azimut A:

http://s7.directupload.net/images/120416/njsdy4vh.jpg (http://www.directupload.net)

What you can see here ist that A is always positiv from north heading clockwise. Attention: Parameter u is negative so you have to draw the Standlinie diagonally opposite of A! The Standlinie is tangential to A. Don’t be lax at this point. Your position will be terrible wrong! Here we go:

http://s1.directupload.net/images/120416/i2w7fp9t.jpg (http://www.directupload.net)

Well done!

For our first example, we loiter around at G1, not changing our position (phi…course and s…distance). Time has come to shoot the sun a second time:

Input values 2nd measurement
Time (T2): 14:25:00
h_b: 24,423°
s: 000,0km (!)
phi: 000,0°

Results of 2nd measurement:
(a) A: 211°; u: -79,64km; Horizontalversatz w: 57,85km (NEW!); Vertikalversatz v: 4,49km (NEW!)
(b) W: 118,9km; V: 63,6km
(c) epsilon: 63°; D: 133,5km

Ok, lets start with (a):

Draw u and A like done above. Because the triangle of SH5 only reaches from 0° to 180° we have to draw 360°-211°=149°:

http://s14.directupload.net/images/120416/yo4wb83i.jpg (http://www.directupload.net)

Now we extend the two Standlinien so that they intersect:

http://s14.directupload.net/images/120416/s37aqb5b.jpg (http://www.directupload.net)

The intersection point (“Markierung 1”) is your true position. But beware: this is your position at WGS relativ to G1. You have to transform (stretch) the intersection point to UTM_120. That’s what the Horizontal- (w) and Vertikalversatz (v) is good for.

http://s7.directupload.net/images/120416/6sulavm8.jpg (http://www.directupload.net)

Vola! Our true position ("Markierung 2") is 56,505°N, 10,01°W. The error is about 0,3km. But consider that all input values are exact ones. If you use your sextant manually and additionally the Nautical Yearbook, the error is expected to be greater.

That’s a lot of drawing we have to do and it’s getting more complex if you change your position from T1 to T2. With (b) and (c) you can minimize your work load:

Using (b) - cartesian coordinates W (horizontal) and V (vertical) in UTM_120:

http://s1.directupload.net/images/120416/37xslcz9.jpg (http://www.directupload.net)

Even better! The often you use the default drawing tools the greater the error will be. You can also use (b) and (c) to check if your drawings are ok.

Using (c), things are more elegant (in my opinion):

http://s1.directupload.net/images/120416/qmfv9hs8.jpg (http://www.directupload.net)

Now let‘s compare our results:
Exact position from SH5: 56,5°N / 10,0°W
Position calculated with the ANM-algorithm: 56,5049°N / 10,0089°W
Using (a): 56,505°N / 10,01°W. The results with (b) and (c) are nearly the same, the variance is in a range of 100-200m.

The display of results summarizes the output values:
Red…(a), blue…(b), green…(c). The yellow marking shows the calculated variance from the exact position.

http://s14.directupload.net/images/120416/p2rd6oxm.jpg (http://www.directupload.net)

The true distance from G1 to our exact position was about 85km. The greater this distance is, the greater the variance will be. This is caused by the curvature of the earth and the plane geometry of the ANM-algorithm.

The results of the graphically methods will depend on your screen resolution. For this example I have used 1920x1080.

That’s all for this time, the next time I will show you how to consider position changes during the two measurements at T1 and T2 („Versegeln der Standlinie“).


Hope you like the results! :salute:

[Sartoris]

Looks very interesting! When do you think you'll be able to release this mod? I hope I'll be able to start using it soon!:yeah:

[silent marshal]

Looks very interesting! When do you think you'll be able to release this mod? I hope I'll be able to start using it soon!:yeah:

It's frustrating: the theoretically background is finished but it seems to be no modders for realization out there. Have to be patient...:zzz:

I will post a second tutorial for dynamic navigation soon (part 2).

[DrJones]

That is looking really great....i got your pm and i will have a look at the documents at it..

Regards

DrJones

[silent marshal]

How to find your own position – Part 2.

Today I will show you how to find your position if you cruise during T1 and T2. You can ship around wherever you like (zigzag). At the end you have to find out the direction (phi…azimut) and distance (s) between G1 (gegißter Punkt) and the position at T2 (time when you shoot the sun the second time). Here we use the example from above.

Input Datas at 2nd mesurement (T2):
Time (T2): 14:25:00
h_b: 24,423°
s: 45,0km
phi: 135,0°

Start the Navigatiosrechner.

Results of 2nd measurement:
(a) A: 211°; u: -63,5km; Horizontalversatz w: 73,2km; Vertikalversatz v: 2,1km; rho: 151°(NEW!); D_s: 33,7km (NEW!)
(b) W: 151,1km; V: 29,1km
(c) epsilon: 79,1°; D: 153,9km

Rho and D_s is the direction and distance for the shift of the 1.Standlinie (“Versegeln der Standlinie”). Notice that rho is different from phi and D_s is different from s. This is because of the transformation from UTM_120 (phi, s) to WGS (rho, D_s).

To find the true position at T2 you have to shift the 1st Standlinie with rho and D_s. Marking 2 is the intersection point of the two Standlinien. We use this point to shift the line. The shifted Marking 2 is now Marking 3.

http://s7.directupload.net/images/120417/ug3bvq2q.jpg (http://www.directupload.net)

Now shift the 1st Standlinie parallel to the originally one. To do that we use the triangle: take the angle between the shift-vector and the 1st Standlinie: 80°

http://s1.directupload.net/images/120417/latbrcxu.jpg (http://www.directupload.net)

Now shift the line by drawing 80° at Markierung 3 and intersect with the 2nd Standlinie (Markierung 4 of the picture below).

http://s1.directupload.net/images/120417/84zjvvxw.jpg (http://www.directupload.net)

“Markierung 4” is the position at T2 in WGS. Next, scale the intersection point to UTM_120 (use w and v), this leads to the true position in SH5 (“Markierung 5”): 56,219°N / 9,743°W. The exact position in SH5 at T2 is 56,235°N / 9,735°W.

http://s7.directupload.net/images/120417/hw547wli.jpg (http://www.directupload.net)

This is a lot of drawing to find the true position. Faster is (b) and (c). The next picture shows the different results: Markierung 8 is the position of option (b), Markierung 9 is the one with (c), Markierung 5 the one with (a) – see above - and finally Markierung 7 is the true position of our boat. You can clearly see that the often you use the map tools, the greater the variance will be (Marking 5 is the baddest result). But every option is good enough for our purpose.

http://s1.directupload.net/images/120417/dx9ymbfk.jpg (http://www.directupload.net)

You can choose which output option you prefer. The variation of the results depend on the resolution of the screen and how exact you are drawing the lines.

Finally the display of the results (explanations see Tutorial 1 some posts above):

http://s7.directupload.net/images/120417/9xb8ho3z.jpg (http://www.directupload.net)


That’s it. It works, it’s easy and it’s fun.

Still waiting for a helping hand for doing all the programming stuff and drawing the GUI. Anybody? No one…??? Anyone???

[Sartoris]

Please modders, make this happen! This is simply a great idea for making the game even more immersive and it deserves your attention. :salute:

[silent marshal]

How to find your position (premium solution) – Part 3

Today I will present you the latest ANM-algorithm development. In tutorial 1 and 2 I have showed you how to find your position with some intricately transformations (Horizontalversatz, Korrekturschlag etc.). This is of course the exact and straight way how to implement the principles of the Höhendifferenzmethode, but it is a bit charmless. I for myself wasn’t satisfied too. So I made some considerations:

What if I use the calculated position, fix the azimuts and recalculate the Radialversatz of T1 and T2 AND use the driven direction and distance from the “Versegelung” (way and direction from T1 to T2) directly out of the nav-map? This would make it possible to handle the graphically tools of the real world Höhendifferenzmethode without any ungainly corrections! This will rock! :rock:

Let me show you what I mean. We use the coordinates and fringe conditions from tutorial 1 and 2 (Date, Time, Versegelung etc.) and calculate the new Radialversätze u_UTM120 at T1 and T2. The computational result is shown below.

http://s7.directupload.net/images/120508/qajewtee.jpg (http://www.directupload.net)

The parameters we need are marked in red. Forget all the other parameters!
First we draw the azimut and the recalculated Radialversatz u_UTM120 (= Standlinie at T1).

http://s14.directupload.net/images/120508/u2wp5ns9.jpg (http://www.directupload.net)

Now the same way for the Standlinie at T2. Attention: in this example we don’t change our position from T1 to T2 (s=0km)!

http://s14.directupload.net/images/120508/nbbhp3hf.jpg (http://www.directupload.net)

The intersection in the right upper part of the drawing is your position – pure and correct at the navigation map, ready to use! :woot:

The deviation of my drawing is about 2km. This is caused by the long distances in conjunction with angles. The default map tools are rather unprecise. But not so bad if you consider that under real world conditions, you can hardly determine your position more precisely than 1sm.

Now we will change our position during T1 and T2: distance 45km, bearing 135°. In the next picture, Standlinie 1 is already visible, Standlinie 2 is drawn with the recalculated u_UTM120 for T2 (different from the one above!): -103,27km

http://s7.directupload.net/images/120508/9ofr2xhu.jpg (http://www.directupload.net)

Now do the “Versegelung” (s=45km, Azimut 135°): the origin is the intersection point of Standlinie 1 with Standlinie 2:

http://s1.directupload.net/images/120508/pyw3l8zw.jpg (http://www.directupload.net)

Now pan the 1st Standlinie with the vector of the Versegelung: first, measure the angle between the vector of Versegelung (135°) with Standlinie 1: 84°

http://s14.directupload.net/images/120508/osfckgty.jpg (http://www.directupload.net)

Now pan Standlinie 1 parallel (45km):

http://s1.directupload.net/images/120508/rn4yh6je.jpg (http://www.directupload.net)

The intersection point with the 2nd Standlinie (Markierung 12) is your true and exact position in SH5. Vola, that’s it! No more corrections needed.

For me, this method is a breakthrough. You do what you will do in real world navigation and it’s absolutely correct. Addintionally you can check your solution with the other three methods shown above. It is planned to give you an option to choose what solution is printed out.

http://s1.directupload.net/images/120508/9vzye3d8.jpg (http://www.directupload.net)

The method shown in this tutorial will be “STANDL. UTM120”. The formal exact procedure of solution ist “STANDLINIE WGS”. There you have to deal with the many corrections for distortion (WGS to UTM120). “KART. KoS” and “POLAR KoS” is for the impatient users or for a quickcheck.

That’s it. Hope you like it.
:salute:

[CaliEs]

How to find your own position – Part 1.


...
Results of 2nd measurement:
(a) A: 211°; u: -79,64km; Horizontalversatz w: 57,85km (NEW!); Vertikalversatz v: 4,49km (NEW!)
(b) W: 118,9km; V: 63,6km
(c) epsilon: 63°; D: 133,5km




Actual i doubt that w "Horizntlversaz" and v "Vertkalversaz" has been correcly calculated.
A rough estimation shows me: w = 52.4km and v = 3.9km.

[silent marshal]

Actual i doubt that w "Horizntlversaz" and v "Vertkalversaz" has been correcly calculated.
A rough estimation shows me: w = 52.4km and v = 3.9km.

Hi CaliEs!

Rough estimation, hmmmm. The ANM-algorithm consists of 82 mathematical equations. It's not easy for me to counter your critique unless I know a bit more about your algorithm.

Maybe you can explain your theory a little bit more, then I can reply seriously and "defend" mine. :03:

But thank you for your comment. :salute:

[karamazovnew]

:hmmm: I hate to be the bearer of ill news, but the Ubi guys didn't allow for the stadimeter to be turned into a sextant. However, somebody could turn the problem on it's head.
Since the game always knows the position of the sub, why not use the formulas in reverse, ending up with the actual height and azimuth of the sun (or other important stars). You could mess up this "Real height" by applying formulas for refraction and horizon drop, weather factor and even sextant error in reverse, to give the player the "observed height".
The player might want to choose to use the "height/azimuth" values directly, not calculate them, but still end up with a nice experience.
Anyway, the whole 2LOP method is flawed in real practice by one important problem: You need to be able to estimate perfectly the distance and course traveled between the 2 readings. The LOP methods are also very sensitive to the error between the real and estimated positions. So make sure you also include the meridian pass method, which only requires a good chronometer for it to work (available at the time). It still requires 2 readings: one at meridian pass to take a very precise latitude and another about 1 hour later to calculate the Angle On Pole, which compared to the GHA gives you LHA and thus longitude (the latitude of the second reading is calculated by dead reckoning, but in one hour you won't mess it up as much). It's also much much faster to calculate. This also circumvents the other bigger issue in the game: the fact that dead reckoning in this game is a joke compared to the real world (no currents, no gyro errors, no helmsman error, no loch).

Of course, the player might not like to "Stay outside" around mid day to wait for the sun height to start dropping, so a sticky "maximum value" would be a god send :)

PS: oh, by the way. You can take a perfect sextant reading even on a stormy sea. I've taken readings on 7 meter waves without any problems. On a sub however, you're only 5 meters away from the water so it's much harder to figure out where the horizon is. Depending on the visibility, it's still doable. I guess it will be up to the player to decide when it's "fair" to use this method, depending on cloud cover and sea state. I don't see how a mod could make that choice.

[quink99]

:hmmm: I hate to be the bearer of ill news, but the Ubi guys didn't allow for the stadimeter to be turned into a sextant. However, somebody could turn the problem on it's head.
Since the game always knows the position of the sub, why not use the formulas in reverse, ending up with the actual height and azimuth of the sun (or other important stars). You could mess up this "Real height" by applying formulas for refraction and horizon drop, weather factor and even sextant error in reverse, to give the player the "observed height".
The player might want to choose to use the "height/azimuth" values directly, not calculate them, but still end up with a nice experience.
Anyway, the whole 2LOP method is flawed in real practice by one important problem: You need to be able to estimate perfectly the distance and course traveled between the 2 readings. The LOP methods are also very sensitive to the error between the real and estimated positions. So make sure you also include the meridian pass method, which only requires a good chronometer for it to work (available at the time). It still requires 2 readings: one at meridian pass to take a very precise latitude and another about 1 hour later to calculate the Angle On Pole, which compared to the GHA gives you LHA and thus longitude (the latitude of the second reading is calculated by dead reckoning, but in one hour you won't mess it up as much). It's also much much faster to calculate. This also circumvents the other bigger issue in the game: the fact that dead reckoning in this game is a joke compared to the real world (no currents, no gyro errors, no helmsman error, no loch).

Of course, the player might not like to "Stay outside" around mid day to wait for the sun height to start dropping, so a sticky "maximum value" would be a god send :)

PS: oh, by the way. You can take a perfect sextant reading even on a stormy sea. I've taken readings on 7 meter waves without any problems. On a sub however, you're only 5 meters away from the water so it's much harder to figure out where the horizon is. Depending on the visibility, it's still doable. I guess it will be up to the player to decide when it's "fair" to use this method, depending on cloud cover and sea state. I don't see how a mod could make that choice.

An excellent post, karamazovnew!

It should help clear away some of the fog! Some of the best modders who might create the MOD needed to make celestial nav happen in SH 5 may not have the needed actual, practical experience in trying to get a good sight on a heaving deck in poor conditions. Those of us who do have this experience might not have a clue as to how to MOD. Your post has given us a good starting point and helped bridge the gap between RW celestial navigators and our excellent modders.

Maybe the best first step would be a dedicated thread where the above two groups can get together and blend their knowledge into an immersive MOD for celestial navigation in SH 5.

Thanks for the posting

[gap]

An excellent post, karamazovnew!

It should help clear away some of the fog! Some of the best modders who might create the MOD needed to make celestial nav happen in SH 5 may not have the needed actual, practical experience in trying to get a good sight on a heaving deck in poor conditions. Those of us who do have this experience might not have a clue as to how to MOD. Your post has given us a good starting point and helped bridge the gap between RW celestial navigators and our excellent modders.

Maybe the best first step would be a dedicated thread where the above two groups can get together and blend their knowledge into an immersive MOD for celestial navigation in SH 5.

Thanks for the posting

Have to agree with quink. I am glad to see that you guys are sharing a lot of knoledge in this thread. All we can do now, is to hope that one day these neat concepts will be put together in a mod! :yep:

As far as I can understand, provided that we know the mathematical function for predicting sun's position, it shouldn't be too complicated for a programmer to implement the respective calculations, if he knows where to look for memory addresses of the few variables that these calculations have to be applied on, namely latitude, longitude and time of the day.

I suppose that TDW knows these addresses, since -if memory serves me well- with his UI he made possible to modify stock settings for historical missions.

Results of the aforementioned function should be offsets values to be used for drawing a sun-like circle on a sextant-like UI with graduated scales on top.

All the map plotting process explained by Silent Marshal, if I got his point, should be done by players for "reverse engineering" their position on the map, based on sextant readings. If so, this aspect doesn't need to be programmed, as Ubisoft once and for all provided us with the needed tools from stock game. :03:

[silent marshal]

Dear Folks!

Long time ago I worked on a method to determine the position of the sub by using the position of the sun. Before I leave the world of SH5 I would share the algorithm with you. Maybe there is someone out there who can use it for his own mod.
If you have any questions, don't hesitate to contactme.

ANM_Formelsammlung-Rev.1.00.pdf (http://www.file-upload.net/download-8491442/ANM_Formelsammlung-Rev.1.00.pdf.html)
ANM_Rev.1.01.pdf (http://www.file-upload.net/download-8491443/ANM_Rev.1.01.pdf.html)


Good luck! :salute:

[tonschk]

Thank you :up: silent marshal :sunny:

Dear Folks!

Long time ago I worked on a method to determine the position of the sub by using the position of the sun. Before I leave the world of SH5 I would share the algorithm with you. Maybe there is someone out there who can use it for his own mod.
If you have any questions, don't hesitate to contactme.

ANM_Formelsammlung-Rev.1.00.pdf (http://www.file-upload.net/download-8491442/ANM_Formelsammlung-Rev.1.00.pdf.html)
ANM_Rev.1.01.pdf (http://www.file-upload.net/download-8491443/ANM_Rev.1.01.pdf.html)


Good luck! :salute:

[DrJones]

Dear Folks!

Long time ago I worked on a method to determine the position of the sub by using the position of the sun. Before I leave the world of SH5 I would share the algorithm with you. Maybe there is someone out there who can use it for his own mod.
If you have any questions, don't hesitate to contactme.

ANM_Formelsammlung-Rev.1.00.pdf (http://www.file-upload.net/download-8491442/ANM_Formelsammlung-Rev.1.00.pdf.html)
ANM_Rev.1.01.pdf (http://www.file-upload.net/download-8491443/ANM_Rev.1.01.pdf.html)


Good luck! :salute:

Hey Mate,

thanks to remind on that. just downloaded the documents once again.
Real Navigation is still a point i wanna realize...

try to implement the algorithm in some functions to see how i can be realize it

Best Regards

DrJones:salute:

[jokerwildcat]

I love this idea. Although Real Navigation is a fantastic mod, this mod is the icing on the cake... if it becomes a mod... and I'm sure in time it will!

[franz_the_cat]

Hi.

Where there is the Astromod with Sextant ?

[gap]

Hi.

Where there is the Astromod with Sextant ?

New UIs by TDW got a sextant-like tool based on the stock stadimeter. CSP Magui by DrJones features on turn a more rudimentary stadimeter, in the form of two scales (one horizontal, one vertical) with degree markings :up:

[Sjizzle]

New UIs by TDW got a sextant-like tool based on the stock stadimeter. CSP Magui by DrJones features on turn a more rudimentary stadimeter, in the form of two scales (one horizontal, one vertical) with degree markings :up:

Now u can use the UZO as sextant with magiu too

[gap]

Now u can use the UZO as sextant with magiu too

That's good :yeah:

I am sorry for the wrong information by the way :88)

[franz_the_cat]

New UIs by TDW got a sextant-like tool based on the stock stadimeter. CSP Magui by DrJones features on turn a more rudimentary stadimeter, in the form of two scales (one horizontal, one vertical) with degree markings :up:


I have wolves of deep instaled
TDW Generic Patch 1_0_168_0 move to the customarily patch with TDW S and TDW C in the folder to activate the second TDW Env and third TDW kernel I once weggelasen but I know not whether it is right at least my sextant is already activated in TDW Generic patch.
Experimental times I've left, and advanced users will be what not recommended by most.
Is something missing?I've done this correctly?

http://abload.de/img/ytbrezn61fmfz3.jpg (http://abload.de/image.php?img=ytbrezn61fmfz3.jpg)

Sjizzle told me in Wolves of Deep first comes the expansion of the solar horizon navigation.
Is it possible in Wovles of Steel sunning horizon navigation apply?