Celestial Navigation in SH4

[6SJ7GT]

UPDATE:
I have place the tools for this in the SH4 Gameplay Mods on this site.
look for the SH4 Nav Package

Over in the real navigation thread in SH4 Mods, we have put together a working method of using celestial navigation in SH4. This is more of a hybrid than a mod, as it only uses Thendashes no sub on map mod, and takes the sub position in a saved game and transfers it to a freeware planetarium program.

There is a tutorial here if you want to try celnav out.

I have put together the Almanacs and tools needed for plotting in a 7zip here.

Below is the readme giving a description of what is involved in getting this working.


This is not a game mod. It works by taking the sub position from a saved game and inserting it blindly into a Planetarium program, where you take your star sights. Don1Reed has extensively tested this and found it to be very accurate. For me, it was a quest to use celestial navigation as it should be used.

Thendash has a small mod to remove the sub marker from the map in SH4 that greatly enhances this package. I have included it in the package with his permission. You can also find the "No Sub On Map" mod here:
http://files.filefront.com/No+sub+on.../fileinfo.html

***** Update *****
The program sh4tostellarium.exe uses command line arguments to put the sub position into stellarium, you don't need to install Python for this. see the sh4tostellarium readme. I have added it to the full package and also uploaded just the program here.

Make sure you get the right program for the version of Stellarium that you are using.

SH4 to Stellarium program.
******************

This package requires the installation of the freeware Planetarium Stellarium and Python open source programming language. . Stellarium is a worthwhile program in itself, and python is a powerful yet fairly easy to use scriptbased programming language. There are numerous tutorials and prebuilt python modules available on the net. I used the pyephem module to create the Almanac pages in Excel.

If you are not familiar with Celestial Navigation, there is a tutorial using a simplified method and the USNO Online Almanac. You can try this with Stellarium if you just want to try celnav.

To Implement this:
1. Install Stellarium: www.stellarium.org

2. Install Python, this version has the windows extensions: Activestate Python

3. After installing start Stellarium so it creates a config.ini file. There should be a link to this in the Stellarium startup directory, if not you can find it under C:\Documents and Settings\***Your login name***\Stellarium.

Open this file and find the [localization] section. Change time_zone to =utc
Save and Close.

4 Put the SH4toStellarium.py script where you can find it. I created a shortcut to it on my desktop, along with a shortcut that runs Stellarium. You have to change a couple of lines in the script to reflect the directories you want. They are marked in the script.

Now run the game. go to the game screen before saving the game. I always save the game to a "Checknav" savegame so the directory stays the same. Note the time you save the game.

You have to convert the game time, which is the time at your base, to GMT.
(GMT is Pearl time + 10 hrs)

After saving the game, run the script, it will ask for the GMT date and time.

Now run Stellarium. it should start at the sub date, time and location. The tutorial has the info in taking "sights" and you are on your way to navigating independently.

The Files in this Archive:

Green TSD.pdf - Time-Speed-Distance sliderule.

Nomograph.pdf - Printable nomograph.

SH4toStellarium.py - Python script (text script).

Time Charts.pdf - Printable GMT conversion charts, use the one you like best.

ups.pdf Universal 8.5 X 11 Plotsheet courtesy of reedsalmanac.com

Short Tutorial on SH4 Celestial Navigation.pdf - The tutorial.

1942 thru 1945 Nautical almanacs - Sun and Star information for reducing sights. see Henning Umland's site www.celnav.de for instructions on using Ageton's tables (compact.zip on his freeware page) plus lots of other info on celestial navigation.

HO-249 Star Sight Wksht for using the HO-249 tables (link in the Tutorial links pages).

sh4tostellarium.exe - program to create startup.sts for stellarium

sh4tostellarium readme.txt - instructions for sh4tostellarium.exe.

Fair skys and smooth sailing,
6SJ7GT / Mike

Edit 12/14/2009 to update links

[6SJ7GT]

Here is another version of the circular Time Speed Distance computer. You can print this out on cardstock to use in the game.

TSD Circular computer

For those who have never used this:
You line up the arrow with your speed on the outer wheel, then you can read time (hours) on the inner wheel vs distance on the outer wheel.

EXAMPLE
line up the arrow (1) with 22(kts), this is also 44000yds/hr. In 1/2 hr you will travel 11 mi or 22000 yards. in 34 hrs you will travel approx. 750 mi.

If you line up the 6 on the inner wheel with your speed, you can read the time in minutes, as the wheel repeats. 6~60~600...
Line up the 6 (60) with 8 kts. In 22 minutes you will travel approx 2.9 mi (5900 yds). You will travel 14 mi in 105 minutes.

Enjoy,
Mike

[Doolan]

This is genius!

[Schultzy]

i really love this but i find that the sub marker still flashes every 5 or so seconds on the map screen (i know it's there zoomed in) I mean when zoomed out. Does anyone else have this problem and is there any way to remove it completely?

Thanks for all the hard work though, this has added a whole new dimension. You're turning me into a navigation addict.

[Doolan]

Originally Posted by Schultzy

You're turning me into a navigation addict.

Glad to see I'm not alone!

Guess who just purchased a cheap plastic training sextant...

[6SJ7GT]

Hello everyone,
It's good to see this getting some use.

i really love this but i find that the sub marker still flashes every 5 or so seconds on the map screen

Schultzy, I have the pulsating pixel too, but just continue to plot and navigate manually. it no longer bothers me as it just confirms the accuracy of this for me.

Doolan, Thanks for the compliment. Check out the REAL NAVIGATION thread in SH4 Mods, Don1Reed has a lot of information on nevigation in general starting on page 7, and could explain the use of an artificial horizon to use with your sextant if you're landlocked and need help.

Mike

[6SJ7GT]

Here are some more goodies for use in navigating, I made some charts for the general operating area. They are small for plotting LOP's, but work good for keeping track of where you are if you are navigating manually.

Navigation Charts

Mike

[don1reed]

I used to have a problem with the "no_sub_on_map" mod also...

until I did a complete, clean, reinstall with both SH3 and SH4.

I use 6SJ7GT's Real Navigation with both sims, SH3 & SH4. Both are working flawlessly.

I've been using Celestial Navigation for over 30 years. This new wrinkle for navigation gives me the opportunity to continue on while beached for good and without the hazard of drowning. lol. Great job, Mike.

[Schultzy]

Thanks for the replies!

I'm glad it's not just me imagining things! I've been trying to look at it as my subordinates showing me their estimates of where we are... The problem is, they seem to be better at it than I am!

Anyway, I shall try the re-install and see how that works out for me.

[don1reed]

another thing you could try, although tedious, is to open & run SH3 each time you reinstall a mod...maybe...just maybe, one of them may be causing a conflict and/or glitch thats causing your problem. Its the only way I know to zero in on a possible culprit.

All the best,

[6SJ7GT]

To All,
My son made a program out of the Python Script. You dont have to install Python, just run the program with command line options to set the directories. I added it to the Celestial Nav package, and uploaded the program separately.

Almanacs and tools for this in an archive here.

Just the program Here.

I think I this is ready for a release tag in the mods forum.

Mike

[6SJ7GT]

To All,

I corrected a few errors to the almanacs, the 1941 to 1945 Nautical almanacs are at this link.
http://hosted.filefront.com/6sj7gt/2231663

I have been doing my navigating by the sun and stars with these. Usually I work up a sight then transfer my position to one of these nav charts.
http://files.filefront.com/SH4+Nav+C.../fileinfo.html

Usually I get several days worth of sights on a plot sheet. I also figured out how to put the nav chart on the table in the control room.



Have fun,
Mike

[6SJ7GT]

To All,
I finally added the 1939 and 1940 almanacs for SHIII per a request from Pisces.

You can find the 1939 thru 1945 almanacs at this link;
http://hosted.filefront.com/6sj7gt/2231663

Enjoy,
Mike

[panzerschutze12ss]

I'm having a problem with your SH4toStellarium.exe program. I am using it for SH3 on a vista 64 rig. When I use the program it takes my savegame data and converts it to the startup.sts script, but inside the file the Lat/Long are reversed.

This is how it wright the script.

date utc 1939/08/07T20:47:00
moveto lon 63.242973
moveto lat 3.668400
script action end

Now the lon number is actually the lat number. To get Stellarium to plot me at right spot I have to reverse the numbers or change the the second line to lat and the third line to lon. I want to use this program because I have downloaded python but have not been able to get it to work properly. Still working on this. Is there something I can change so I do not have to cheat and see my position by opening the startup script.

[Pisces]

Same here.

Aside from that, I noticed http://www.stellarium.org/wiki/index.php/Scriptson the Stellarium Wiki Scripts-page that the latest version (v 0.10.0) doesn't have a scripting engine (anymore). Version 0.10.1 should have a better script engine once it is released. I have 0.10.0 installed and starting Stellarium up by the start-up file doesn't work. The program starts, does some initialisation but then kicks back to desktop. So I guess we are forced to use an older version for the time being.


Older Windows versions:

http://sourceforge.net/project/showf...ckage_id=52047

@ 6SJ7GT Also note on that Scripts Wikipage there have been changes in the date/time format used for versions since 0.9.x.

Originally Posted by Stellarium Wiki

Note for version 0.9.x

Scripts written for versions previous to 0.9.x of Stellarium might date date command with the argument is a format like this:
date utc 2008:4:24T12:00:00
date local 2008:4:24T12:00:00

This will cause a problem in version 0.9.x - you need to update such scripts so that the date command they look like this:
date utc 2008-04-24T12:00:00
date local 2008-04-24T12:00:00