Celestial Navigation in SH4

[Pisces]

Originally Posted by CaptainMattJ.

i dont get what erxactly this mod does.....? Are you talking about navigating with the stars only? if so, then you should be able to see your sub like you normally would at night, and at day you cant see where you are. thats how they did it back then. all they had was the stars to navigate, and stars can only be seen at night. therefore, it should be a simple (maybe?) mod in the folders. when its take sub marker off map. at night put it back on.

This mod (actually, it is not in any way a mod-ification, as nothing in the game itself gets changed) gives you an external way to (accurately) simulate measuring the height of celestial objects. The sextant mods sofar made for SH3 and SH4 are just to crude to be usefull. With those measurements you can calculate where you are in the world.


Which star can you also see during the day? Does it not rise and set?

But seriously now, you should also be able to use the planets and moon as targets to take fixes from. If the almanac or ephemerides contains their positions. It's just easier to use the stars as they do not move on their own. Well, not measurable for this purpose anyway. Planets, sun and moon move a little bit every day, so you'd have to recalculate (extrapolate) their position in the heaven every new sighting you do.


The game stores the location of the sub in the savegame (in name_of_savegame.map). The python script reads this location and converts it to a latitude and longitude coordinate for Stellarium. The python script asks for a time and date (as I don't think it is stored in that file, though it must be hidden somewhere I'm sure, but nobody found it) and should generate a Stellarium startup script for it. Actually, to make it work you do not need to enter the time and date of the game. Your current time and date also works, it's just not immersive as you'll see a different sky. In Stellarium you measure the altitude (height) of 3 or more celestial object in question and afterwards you do the numbercrunching (mostly using tables) to develop your position plot. The celestial object positions are in the almanacs that 6SJ7GT generated for those years, or you can use the link I provided some time ago (my last message above) to the new USNO online almanac.

You'll have to keep track of your own movement inbetween skyfixes yourself through the use of deadreckoning. Meaning, plotting your movement on the map based on your speed and course. Whether or not the sub symbol is shown on the map is optional. I don't even think you can switch it on/off at the change of redlight (sunset and sunrise)