Celestial Navigation Revisited

[CaliEs]

Originally Posted by 11Bravo

We started on the Equator and shot 3 navigation stars separated by about 120° in bearing to get a nice shaped error triangle. ...

Another question...

Is this a typing error?

[11Bravo]

Yep, that was a typo.

Here is the corrected plot.

[vanjast]

Remember that you want to simplify it as far as possible.
If you make it complicated (ie: exit game run other proggy), kinda destroys the immersion.

PDFs, charts and in-game stuff work better

[P_Funk]

I much prefer in game methods. I'd rather plot a dead reckoned course on a piece of paper in my lap than have to alt tab and use another program (I consider pen and paper on my computer desk as being in game ).

I honestly think it would be a really cool thing to have a bunch of track charts from previous patrols just kicking around my stack of papers.

Speaking of which, how would I go about drawing my own track chart? I suppose it means having a scale set up to measure nautical miles in centimeters or something as you plot it on your paper. All the track charts of actual U-boat patrols I've seen were mostly on blank paper or grid maps with no subgrids so it was very bare looking.

Anyone have any suggestions on websites for this? I'm gonna go do my own googling but since there are people here who are well deeper into this maybe you have some insights for me. I may just make my own track chart for my next patrol on a whim to see if I can suffer keeping up the level of detail necessary to pull off a full Real Nav patrol.

[LemonA]

Originally Posted by P_Funk

I honestly think it would be a really cool thing to have a bunch of track charts from previous patrols just kicking around my stack of papers.

Speaking of which, how would I go about drawing my own track chart.

Try using google.maps, if you have an google-email-account. Collect Lat/Long + Time at every DR-position and put it in the maps. Connect the DR-positions. Then you get the route. Save it. Make it available to the public.

[11Bravo]

@vanjast
@P_Funk



In-game + pencil/paper + simple as possible = my goal.

The biggest challenge to this will be the almanac I suspect. I am using a computer program currently for convenience. But I also went to the other extreme of solving the nautical triangle directly using only a table of logarithms, no calculator. Using presolved almanacs is the middle path, and probably historically accurate. Hopefully we can use an existing publication and not have to make a custom one from scratch.

@LemonA

That is pretty cool. I will have to check that out. Does it accept degree minute format?

That reminds me that we need a ruler to better measure lat lon coordinates for reporting or plotting on paper. I made one once and I will do that next.

[P_Funk]

Originally Posted by LemonA

Try using google.maps, if you have an google-email-account. Collect Lat/Long + Time at every DR-position and put it in the maps. Connect the DR-positions. Then you get the route. Save it. Make it available to the public.

Thats a cool idea. My goal longterm is to make at least one full patrol that has a proper KTB in the real format used including all attachments. This means the main KTB with full descriptions of everything that happens along with grid references, firing reports, and track charts, maybe even a radio log since GWX adds a butt load of those and I can easily write my own and send update reports to BDU to simulate this and record them in my log. I already made some templates for typing them up in photoshop so that they appear like captured documents preserved, stamped, and microfilmed for archives by the British, and I can easily I figure scan any track charts I make too since I have a scanner.

I am a bit of a role player.

Originally Posted by 11Bravo

@vanjast
@P_Funk



In-game + pencil/paper + simple as possible = my goal.

The biggest challenge to this will be the almanac I suspect. I am using a computer program currently for convenience. But I also went to the other extreme of solving the nautical triangle directly using only a table of logarithms, no calculator. Using presolved almanacs is the middle path, and probably historically accurate. Hopefully we can use an existing publication and not have to make a custom one from scratch.

Well I imagine it would be pretty ridiculous to try and print out a copy of the almanac given how many possible locations and days and times over the 6 years of the war there would be. Also, there probably isn't an easy way to find a real almanac from that time period anymore in print.

I do agree that the simple and authentic pencil/paper method is most appealing. The more I have to plug something into a modern apparatus the more it detracts from the fun of it. I already use a calculator for some of my TDC calculations and I don't want to go much past that for anachronistic affectations.

I'm not only excited by your work Bravo, but also by your attitude about it. A project that appeals to me on multiple levels.

[11Bravo]

Does anyone know the authentic way to report latitude and longitude?

Is it latitude first or longitude?
Do you put the N/S and the E/W in front of or behind the value?
And any spaces between anything?

@P_Funk

Thanks!

[11Bravo]

Originally Posted by reaper7

Haven't received a mail, can you send it again - or PM me here.

Sent you mail a few days ago. Your app seems to work fine. It is a little strange to see the clocks work correctly in SH3.

Only problem is running a second app along with SH3 makes testing sloooowww on my old computer.

[urfisch]

extremly interesting topic!!! great work so far!

[LemonA]

Most nav charts have first Lat then N or S then space then Long then W/E:
54°34.897'N 011°16.063'E

The "Nautical Char Ruler" would be extremely usefull. Any chance to release it?

Nautical almanacs '39-'45, SightReducTables etc. already exists and as far as I know for celestial calculation useable.

162 pages for year 39


400 pages for Part "Lat 40-60"

[11Bravo]

@LemonA

Thanks for that information. Yes, I will release the chart ruler tonight after work.

[P_Funk]

Originally Posted by LemonA

400 pages for Part "Lat 40-60"

Yikes. That'd be a mammoth printer undertaking to get every book we need.

[palatum]

Could the nautical almanac be integrated ingame? Like the ship recognition manual? Or would it be to big?

-Pal

[11Bravo]

@urfish

Thanks Kaleun! It has been very challenging and fun for me.

@LemonA

I uploaded the chart ruler even though voyage 3 is far from complete.

@palatum and P_Funk

There would be no practical way of presenting the very precise information found in a nautical almanac as in-game graphics. There might be a way to create a condensed version of low precision data that would cut down on printing. There might even be a way to put something useful in-game, like a perpetual almanac or sunrise/sunset table in-game. It all depends on how much accuracy is necessary. If the method is limited to 30 km, we only need celestial data good to 10 arc minutes, not 1 arc minute or arc seconds.

Most likely the final solution will involve pdf's that the player would print out, although the actual books should work better.