Is SH5 A Good CelNav Practice And Test Bed?

06-26-18, 08:31 PM

In a word, no. At least not according to my explorations in other threads and experimentations. If anyone knows differently, please advise me.

Given the SH series was never really intended to be a CelNav simulator platform it would be unfair to condemn all the beautiful work which Ubisoft has put into the software as well as all the talent which has been put into the modding. Super kudos to all!

However...

The purpose of this post/thread was to address the CelNav applicability for others who may wish to know.

There are two main issues which are the culprit...

An Inaccurate Star Field - All of the nautical almanacs of celestial bodies positions are based on the precise positions in the Celestial Sphere. Inaccurate positions can net LOP fixes which are hundreds or thousands of miles off the right place. The hazards of this are obvious.
A Flat World Map - The Mercator grid of the map essentially leaves the N/S distances unusable outside of the Tropic of Cancer and the Tropic of Capricorn. Actually, they only seem to be accurate at the Equator, but becomes less accurate north or south with ever greater error on an exponential curve.

In closing, I encourage everyone to use SH for its intended purpose for which has been created and improved via modding. Perhaps the people at Ubisoft will read this and take the SH series to this next level of true mariners. Given the time frame of the SH series is before GPS, LORAN, etc., it seems to me improving the star field and map to resemble the real CelNav experience would add a new level of realism to SH. After all, how did those submarine commanders know how to get from one place to another?

Sean C · 06-26-18, 11:46 PM

A working celestial navigation simulation would be a dream come true for me. There was a sailing simulator which, for a while, claimed to be able to simulate the practice. (The name escapes me at the moment.) However, it too was found to be inaccurate and the developer discontinued working on it.

I wonder if a table of meridional parts (such as that found on page 667 of Bowditch, explanation on page 558) could be used to overcome the "flat Earth" problem. In any case, you'd still be stuck with the inaccurate sky. But, it might mean one less problem to solve for the devs, a modder or anyone else clever enough to find a solution.

Oh, well. I suppose I'll continue to keep a lookout for a sim that includes celestial. I'll let everyone know if I find anything.

vdr1981 · 06-27-18, 01:26 AM

http://www.subsim.com/radioroom/showthread.php?t=206103

03-16-19, 05:12 PM

@Nathaniel B., I might have a solution.

Quote:

Originally Posted by vdr1981

http://www.subsim.com/radioroom/showthread.php?t=206103

Hi VDR, Thank you and sorry for the delay. I just re-found my thread.

The answer to the question in my OP seems to be in the affirmative. I am performing some tests using only CelNav and DR to go from a Point A to Point B. Since I enjoy the realism of TC=1 it will take awhile, but I will report back.

I understand how to use a sextant (I use one in real life), but I am trying to understand how to use it in combination with a chronometer (clock, watch, etc.) to calculate longitude. I think I understand, but I won't know until I can test.

vdr1981 · 03-16-19, 05:59 PM

Quote:

Originally Posted by Capt Codetrucker

@Nathaniel B., I might have a solution.

Hi VDR, Thank you and sorry for the delay. I just re-found my thread.

The answer to the question in my OP seems to be in the affirmative. I am performing some tests using only CelNav and DR to go from a Point A to Point B. Since I enjoy the realism of TC=1 it will take awhile, but I will report back.

I understand how to use a sextant (I use one in real life), but I am trying to understand how to use it in combination with a chronometer (clock, watch, etc.) to calculate longitude. I think I understand, but I won't know until I can test.

Welcome back Capt Codetrucker.

Very few people use full potential of this single best mod ever developed for any SH game (TDW's Real Navigation) but unfortunately I'm not one of them...

For full hardcore celestial navigation, Sjizzle is your man...

Luckily, he's active these days on forum so you may wish to check his threads and ask him few questions...

Happy hunting...and navigating...

03-17-19, 01:32 AM

Quote:

Originally Posted by vdr1981

Welcome back Capt Codetrucker.

Very few people use full potential of this single best mod ever developed for any SH game (TDW's Real Navigation) but unfortunately I'm not one of them...

For full hardcore celestial navigation, Sjizzle is your man...

Luckily, he's active these days on forum so you may wish to check his threads and ask him few questions...

Happy hunting...and navigating...

Thank you, but it sounds like you are suggesting TWoS is not the best option for real CelNav, but Sjizzle would be? Is this correct or did I miss something?

My understanding (or lack of it) is not your fault. It seems the window of my mental clarity has come and gone for now.

But, I press on.

06-26-18, 08:31 PM	#1
Capt Codetrucker Stowaway Posts: n/a Downloads: Uploads:	Is SH5 A Good CelNav Practice And Test Bed? In a word, no. At least not according to my explorations in other threads and experimentations. If anyone knows differently, please advise me. Given the SH series was never really intended to be a CelNav simulator platform it would be unfair to condemn all the beautiful work which Ubisoft has put into the software as well as all the talent which has been put into the modding. Super kudos to all! However... The purpose of this post/thread was to address the CelNav applicability for others who may wish to know. There are two main issues which are the culprit... An Inaccurate Star Field - All of the nautical almanacs of celestial bodies positions are based on the precise positions in the Celestial Sphere. Inaccurate positions can net LOP fixes which are hundreds or thousands of miles off the right place. The hazards of this are obvious. A Flat World Map - The Mercator grid of the map essentially leaves the N/S distances unusable outside of the Tropic of Cancer and the Tropic of Capricorn. Actually, they only seem to be accurate at the Equator, but becomes less accurate north or south with ever greater error on an exponential curve. In closing, I encourage everyone to use SH for its intended purpose for which has been created and improved via modding. Perhaps the people at Ubisoft will read this and take the SH series to this next level of true mariners. Given the time frame of the SH series is before GPS, LORAN, etc., it seems to me improving the star field and map to resemble the real CelNav experience would add a new level of realism to SH. After all, how did those submarine commanders know how to get from one place to another?

06-26-18, 11:46 PM	#2
Sean C Grey Wolf Join Date: Jun 2017 Location: Norfolk, VA Posts: 984 Downloads: 16 Uploads: 2	A working celestial navigation simulation would be a dream come true for me. There was a sailing simulator which, for a while, claimed to be able to simulate the practice. (The name escapes me at the moment.) However, it too was found to be inaccurate and the developer discontinued working on it. I wonder if a table of meridional parts (such as that found on page 667 of Bowditch, explanation on page 558) could be used to overcome the "flat Earth" problem. In any case, you'd still be stuck with the inaccurate sky. But, it might mean one less problem to solve for the devs, a modder or anyone else clever enough to find a solution. Oh, well. I suppose I'll continue to keep a lookout for a sim that includes celestial. I'll let everyone know if I find anything. __________________ If you have a question about celestial navigation ... ask me! Celestial Navigation Spreadsheet

06-27-18, 01:26 AM	#3
vdr1981 Navy Seal Join Date: May 2010 Location: Србија Posts: 6,078 Downloads: 581 Uploads: 13	http://www.subsim.com/radioroom/showthread.php?t=206103 __________________ Best regards... Vecko The Wolves of Steel v2.2.25_SH5 Expansion Pack_Full The Wolves of Steel v2.2.xx to v2.2.25 - Update PDF Install Instructions How to report an issue If You wish to support my work...