RealNav navigation..

vanjast · 05-17-07, 03:28 PM

As I mentioned before, this is my new career and generally the first serious test of the RealNav mod. Well I'm happy to say it's works well so far, and I would like to complete the first mission before I make a full report.

Things I've noticed so far:
- I reduced my max time compression to 256x as the helmsman does not stay on course and you have to correct him (maybe this can be 'modded' to make life easier).
- I regularly 'get lost' out in the open sea but rely on my sextant and almanac to fix my position.
- In between readings and with lousy weather I keep notes on course, times and speed.

It has worked out pretty well as with this example :-

I'd been floating around the Outer Hebrides of Scotland when calm weather arrived. I decided that the island down to the SW was a good aiming point for a little test. I'd last got a FIX some 6 hours prior to this, and so changed course and went.
In calm seas one does not have to correct the helmsman that much - so 256x it was.
When close I made a course correction, hopefully to bring me within sight of land.

Turned up the time compression and then later turned down to normal time - just in time to see the island. I nearly beamed passed it.

With this mod I've found that you have to keep your wits about you.
The higher your time compression the quicker you'll get lost.
Use the ruler, marker, protractor and bearing tool continously
Take it slow, boring I know, but it's very rewarding to actually know where you are, and you did this on your own.
This is all before you start sinking ships

Notewire · 05-17-07, 04:53 PM

Nice Navigating Vanjast, I have been using the same method - and I love it. It really gives you the feel of Sailing - not just warping around a map shooting at things. I couldn't be without it myself.

Happy Hunting,
Notewire

vanjast · 05-17-07, 05:53 PM

That's for sure Notewire

I'm currently at the western approaches and decided to patrol here instead of my assigned grid (too far away). I went down to take a hydrophone reading and picked up a ship in the east.

Now previously (before this mod) I'd turn around and star-trek myself down there, sink the ship and go elsewhere - no problem.

This time:
I note the time.
Turn around, surface and max speed - take notes of speed and course.
While on the way Fix my turn-around position.
When ship is sighted note time (calculate distance travelled) and begin attack. i sunk the ship by gunfire as the sea was flat.
Then returned to original course, taking notes of time, speed etc..

With all these times, speeds, courses, etc I use the Marker pen to note my current position.

As you all can see, it's a s.h-i't load more work to do, but if you think about it in RL, this is no more than what you'd do on a sailing boat.

Georg_Unterberg · 05-18-07, 07:19 AM

great job vanjast!

I think real navigation adds a new dimension to this game. I hoped, they had done it in SH4 but I guess only a few people cared about it.

Before I dare to try to navigate for real: What almanac data do you use, vanjast? I wonder if the SH3 team did in fact use the ephemeris data from 1939-1945 to model the constellations. I only have almanac data from 1950 up to now.

I have tried to triangulate position by using 3 stars. I get varying results in position accuracy - best was 10nm so far (which is pretty good I think) and worst was 80nm error. Its impressive to see that all the constellations are in fact there where they should be!

vanjast · 05-18-07, 09:18 AM

Quote:

Originally Posted by Georg_Unterberg

great job vanjast!

What almanac data do you use, vanjast? I wonder if the SH3 team did in fact use the ephemeris data from 1939-1945 to model the constellations. I only have almanac data from 1950 up to now.

the one I use is here:-
http://www.vanjast.com/NavMod/RealNav_ReadMe2.zip (1.7MB)
or
http://www.subsim.com/radioroom/showthread.php?t=113975

I made this up for 1939-45 from a celestial proggy I bought.

Quote:

Originally Posted by Georg_Unterberg

I have tried to triangulate position by using 3 stars. I get varying results in position accuracy - best was 10nm so far (which is pretty good I think) and worst was 80nm error. Its impressive to see that all the constellations are in fact there where they should be!

I must still try this - maybe you want to write up a doccy on Triangulation

Georg_Unterberg · 05-18-07, 09:08 PM

vanjast,

got your sun almanac and its a pretty good table

calculating longitude by sunrise/sunset should be no problem now. BTW have you noticed that ship chronometer (in lower right corner) does not show GMT? Weird thing. It seems to show local time (and local time seems to be something else). Noticed that because all star calculations were wrong when I used missions in western atlantic (far off greenwich meridian).

As for triangulation, I use a german freeware tool called "Nautic Tools" to make the calculations. It's simply too much workload to do it with pen, paper & book all the time.

The "nautic tools 1.20" from Markus Eisenbart is a mighty fine program (but in german)

http://www.nautictools.de/

I also need help with removing the "tailfin" course marker of my own position. I don't know how to remove it. It was great for testing, but it needs to be removed for real navigation. do you know how??

05-17-07, 03:28 PM	#1
vanjast Sea Lord Join Date: Jun 2006 Location: Somewhere else now Posts: 1,660 Downloads: 801 Uploads: 4	RealNav navigation.. As I mentioned before, this is my new career and generally the first serious test of the RealNav mod. Well I'm happy to say it's works well so far, and I would like to complete the first mission before I make a full report. Things I've noticed so far: - I reduced my max time compression to 256x as the helmsman does not stay on course and you have to correct him (maybe this can be 'modded' to make life easier). - I regularly 'get lost' out in the open sea but rely on my sextant and almanac to fix my position. - In between readings and with lousy weather I keep notes on course, times and speed. It has worked out pretty well as with this example :- I'd been floating around the Outer Hebrides of Scotland when calm weather arrived. I decided that the island down to the SW was a good aiming point for a little test. I'd last got a FIX some 6 hours prior to this, and so changed course and went. In calm seas one does not have to correct the helmsman that much - so 256x it was. When close I made a course correction, hopefully to bring me within sight of land. Turned up the time compression and then later turned down to normal time - just in time to see the island. I nearly beamed passed it. With this mod I've found that you have to keep your wits about you. The higher your time compression the quicker you'll get lost. Use the ruler, marker, protractor and bearing tool continously Take it slow, boring I know, but it's very rewarding to actually know where you are, and you did this on your own. This is all before you start sinking ships

05-17-07, 04:53 PM	#2
Notewire Soundman Join Date: Aug 2006 Posts: 143 Downloads: 75 Uploads: 0	Well Done Nice Navigating Vanjast, I have been using the same method - and I love it. It really gives you the feel of Sailing - not just warping around a map shooting at things. I couldn't be without it myself. Happy Hunting, Notewire

05-18-07, 07:19 AM	#4
Georg_Unterberg Machinist's Mate Join Date: Apr 2005 Location: Germany Posts: 122 Downloads: 28 Uploads: 0	great job vanjast! I think real navigation adds a new dimension to this game. I hoped, they had done it in SH4 but I guess only a few people cared about it. Before I dare to try to navigate for real: What almanac data do you use, vanjast? I wonder if the SH3 team did in fact use the ephemeris data from 1939-1945 to model the constellations. I only have almanac data from 1950 up to now. I have tried to triangulate position by using 3 stars. I get varying results in position accuracy - best was 10nm so far (which is pretty good I think) and worst was 80nm error. Its impressive to see that all the constellations are in fact there where they should be! Last edited by Georg_Unterberg; 05-18-07 at 09:05 AM.

05-17-07, 05:53 PM	#3
vanjast Sea Lord Join Date: Jun 2006 Location: Somewhere else now Posts: 1,660 Downloads: 801 Uploads: 4	That's for sure Notewire I'm currently at the western approaches and decided to patrol here instead of my assigned grid (too far away). I went down to take a hydrophone reading and picked up a ship in the east. Now previously (before this mod) I'd turn around and star-trek myself down there, sink the ship and go elsewhere - no problem. This time: I note the time. Turn around, surface and max speed - take notes of speed and course. While on the way Fix my turn-around position. When ship is sighted note time (calculate distance travelled) and begin attack. i sunk the ship by gunfire as the sea was flat. Then returned to original course, taking notes of time, speed etc.. With all these times, speeds, courses, etc I use the Marker pen to note my current position. As you all can see, it's a s.h-i't load more work to do, but if you think about it in RL, this is no more than what you'd do on a sailing boat.

05-18-07, 09:08 PM	#6
Georg_Unterberg Machinist's Mate Join Date: Apr 2005 Location: Germany Posts: 122 Downloads: 28 Uploads: 0	vanjast, got your sun almanac and its a pretty good table calculating longitude by sunrise/sunset should be no problem now. BTW have you noticed that ship chronometer (in lower right corner) does not show GMT? Weird thing. It seems to show local time (and local time seems to be something else). Noticed that because all star calculations were wrong when I used missions in western atlantic (far off greenwich meridian). As for triangulation, I use a german freeware tool called "Nautic Tools" to make the calculations. It's simply too much workload to do it with pen, paper & book all the time. The "nautic tools 1.20" from Markus Eisenbart is a mighty fine program (but in german) http://www.nautictools.de/ I also need help with removing the "tailfin" course marker of my own position. I don't know how to remove it. It was great for testing, but it needs to be removed for real navigation. do you know how??