[TEC] Real navigation Tutorials

[Japo32]

going into documents SH5/data/GameplaySettings.cfg and changing the NoStabilizeView to False, doesn't change anything.. it continues waving up and down. Imposible to calculate a real altitude angle of the sun or any star....

[gezahu]

Originally Posted by Japo32

going into documents SH5/data/GameplaySettings.cfg and changing the NoStabilizeView to False, doesn't change anything.. it continues waving up and down. Imposible to calculate a real altitude angle of the sun or any star....

Not that. The cfg file you change is in mydocuments/*user*/SH5 or something... where the savegames are not the game.

[gezahu]

No matter what I cant make it work. My readings is off....

[Sir Pappnase]

In your 2nd tutorial, where comes the sextant minutes of 51 from? Ist it from the Altitude? that 5142?
The 40 you are refering to below, is that the calculated altitude° Hc in the excel file?
I downloaded the file aswell, but unfortunately it shows #WERT! (~#VALUE!) in the declination line


I also cant get the sextant up. do have have to press a button, once i point it on the horizon? I only can move it up and down like 20° I cant even measure the altitude.

I've been calculating my LAT for the past 3hrs but I just can't figure why my math is incorrectly. Could someone please help me out?

I'm using Tutorial TDC as my mission(TWOS), starting location is 46.41N , 15.10W

My math below:
1/1/1941, sun's highest point is at 9am local or 10am GMT.
Sextant Altitude=56.31, DEC is S23.04
ZD=89.60-56.31=33.29
Latitude=33.29-23.04=N10.25

What have I done wrong here? Why is my LAT 10.25N instead of 46.41

Any help would be appreciated!

[Sean C]

Well, the good news is that your math is correct. The bad news is that it seems your noon altitude is wrong.


The equation for figuring out the predicted altitude of a celestial body is:


asin(sin(Dec)·sin(Lat)+cos(Dec)·cos(LHA)·cos(Lat))


"Dec" is the declination of the body, "Lat" is your latitude and "LHA" is the local hour angle of the body. By definition, at local noon, the LHA is 0°. So, plugging in the other figures from your example gives us:


asin(sin(-23°04')·sin(46°41')+cos(-23°04')·cos(0°)·cos(46°41') = 20°15'


In other words, the altitude you should have measured given these parameters is 20°15'. Subtracting this from 90° (or 89°60') gives 69°45'. Subtracting the declination, 23°04', from 69°45' gives 46°41' ... your DR latitude.


Now, why your altitude is so wrong is another question altogether.

[vdr1981]

Originally Posted by Lymark1

I've been calculating my LAT for the past 3hrs but I just can't figure why my math is incorrectly. Could someone please help me out?

I'm using Tutorial TDC as my mission(TWOS), starting location is 46.41N , 15.10W

My math below:
1/1/1941, sun's highest point is at 9am local or 10am GMT.
Sextant Altitude=56.31, DEC is S23.04
ZD=89.60-56.31=33.29
Latitude=33.29-23.04=N10.25

What have I done wrong here? Why is my LAT 10.25N instead of 46.41

Any help would be appreciated!

Try it in the campaign. I don't think that time and date are correct in single missions...

[sckallst]

So I've jumped back in to sub-simming recently. I've always played Real Nav/no map contacts, but this time I've decided to go all-in on celestial navigation with no or minimal help from the in-game navigator and scripts.

I understand cel nav well enough to get by, but I'm having a tough time getting accurate-enough sights with even small wave motion. I'd really like to be able to mess around with three star fixes and such, but I'm just bouncing around way too much.

I see others in this thread have had this issue as well. Any new advice or fixes out there?

Thanks to all who've posted the various tutorials and other resources here and in the SH3/SH4 forums. Really looking forward to doing navigation to add something to the game.

[Macgregor the Hammer]

This is really good stuff! It's almost identical to the Coast Guard Auxiliary Celestial Navigation lesson syllabus I studied when I was trying to get my sailing master's license back in the '89's. I think I still have the books somewhere. Thanks for posting!

[MrArt]

Hello!

I am using Real Navigation with TWOS. I started a new campaign. When I used the sextant to calculate the coordinates I saw that the sky was behaving very strangely. If my time zone is GMT +1 then I must use the Nautical Almanac with a GMT -1 time, and if the time zone is GMT -5
then I have to use GMT +5 time (checked this with Stellarium). Only in this case will all the calculations be correct. How to fix it?

And is there a way to increase the sextant zoom level to increase the accuracy of observations?

[Aktungbby]

J0hnShadow! & MrArt!

[Sean C]

Originally Posted by MrArt

If my time zone is GMT +1 then I must use the Nautical Almanac with a GMT -1 time, and if the time zone is GMT -5
then I have to use GMT +5 time

I'm not sure, but this may be due to the fact that there are two different conventions for naming nautical time zones.


For example: let's say you're at 60° west longitude. Some sources would label this as "GMT -4", because the time there is 4 hours before the time at Greenwich. However, other sources would label it as "GMT +4", because you have to add 4 hours to get to GMT. It's the same thing, just two different ways of looking at it.


Personally, the vast majority of examples I have seen list west longitudes as negative and east as positive. But, I have seen it the other way around occasionally. IIRC, the latter is more popular in European countries and the former in the U.S.


There was a discussion about this very topic on NavList some time ago. I'll try and see if I can find it ...


[EDIT] Here it is: Time Zone Conventions.