Real Navigation Mod

[ichso]

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.

Originally Posted by ichso

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
http://www.subsim.com/radioroom/showthread.php?t=117081

[ichso]

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]

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

[ichso]

Originally Posted by ronbrewer

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/show...=114812&page=4
Poor Sailor uploaded his Cameras.dat there.

http://www.subsim.com/radioroom/show...=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]

Thanks for the links, ichso. I'll give those a try for the RealNav mod install.

[ichso]

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]

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]

Just 5nm off...not bad. IRL its easy to see that far at sea. Nice going

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,

If anyone of you see Vanjast. Tell him that i got the sextant working draggable in SH4 now....

http://www.subsim.com/radioroom/show...d=1#post575113

Originally Posted by don1reed

Just 5nm off...not bad. IRL its easy to see that far at sea. Nice going

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

[ichso]

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]

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.

Originally Posted by don1reed

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.