Real Navigation with SH4

[don1reed]

Submarines, by their very nature are aggressive and surreptitious entities, and as such usually don't revert to the tactics of their targets; however, zigs und zags are 45 degree course changes from the mean course. Seldom are they precisely timed. More often than not they are randomly timed turns. (keep the enemy guessing)

The ship's navigator has his hands full, as usual, but more so due to the extra plotting involved. As you would expect, DR is the order of the day and extra sharp chart/plotting construction/drafting techniques are a requirement. Sloppiness with pencil, protractor, & compass just adds to the inherent errors of dead reckoning.

edit: The zig-zag has been and remains with us since the dawn of sail and the need to beat upwind. New terms evolved to depict their presence, such as CMG, SOG, SMG, CTS (course made good, speed over ground, speed made good, course to sail).

The only faith given the navigator is what unfolds in the heavens above.

Cheers,

[don1reed]

I swear this old brain of mine

Too late to switch-over to a newer more supple one

If I were a convoy commander at the onset of a passage, or via radio, might order the ships to come to course such-n-such at my command:

"Execute, execute, execute!" <------Random

or...


prearrange a turn sequence: given speed & direction & time <------predictable by lurking submarines.


Convoy navigator: Has true course plotted from A to B. All he has to do is plot the zig-zag directions from the mean course via DR plots.

[beretta5]

is there version for SH4 1.5 of the navigation mod?

[don1reed]

Howdy, beretta5 & Welcome aboard.

Python & Stellarium are standalone freeware pgms and are used simultaneously along with SH4 no matter the version. Our hats are off to, 6SJ7GT and castorp345, for getting the Python script this usable for navigation.

cheers,

[jbt308]

Amazing all the work that you guys have put in, and I must admit that I'm highly intrigued, but I would definately have to study up on my trig/geometry/astronomy/etc...

I'd like to posit something I'd call a "lite" solution, maybe an alternative to using the full on real navigation, or at least, in addition to a real navigation addon. Would there be anyway to create a button that would give you the general coordinates of the subs location. And I say general, because I'm wondering if you could weigh the results based on:

1. current weather patterns the time the button is pressed
2. rank of the highest officer/capitan
3. a random error of +/- 10%

I agree with you all that immersion is definately enhanced when you start implenting things from the real world, but I would think a lot of people would use the lite version as well. It would add something, albeit, not to the extent that the full would.

Just a thought.

[don1reed]

Howdy, jbt308.

I'm a user too and I couldn't agree with you more. You've hit on the magic of SH4, I believe.

For one, no matter how skilled or knowledgeable the player is, there is always something here for everyone.

Secondly, the gifted modders will, no doubt, examine your idea and eventually come up with something usable for everyone.

We're just playing here, now, toying with the idea of actual navigation using SH4. It's not as difficult as it appears at first blush, once the basics are learned....but, it is time consuming.

I believe 6SJ7GT is working on a beginner's package even as we speak. Once he gets it perfected, I'm sure he'll share with all.

cheers,

[jbt308]

I completely agree with you, it never ceases to amaze me what the modders come up with, and quite honestly, they usually make the game what it should be. I think this sort of brainstorming is can only be helpful, and I'm looking forward to see what comes of it.

Thanks again to all that make the games great!

[don1reed]

Hey, Mike.

I just got your script to work with SH3 and shortly will have hc's mod of your script working with SH3 also. WooHoo.

[Pisces]

6SJ7GT:

You're a genius. A simple and elegant solution to take the position data from a savegame (and still keep it hidden from the player's view!), and use a propper star/planet projection tool instead of Silent Hunter's limited capabilities in this. Sofar SH(3)'s limited measuring accuracy hold me off from learning/trying celnav. But now I feel something itching (has been itching my whole life actually) that needs to be scratched soon. I only hope someone can create a more direct solution (like write a simple windows application) instead of needing to install this Python stuff. This sounds like a bit of overkill to me.

Ok what's next. Celnav sliderulers?

[6SJ7GT]

Howdy all,
Looks like this is catching some interest, so I created a tutorial on a simplified method of taking star sights in the game. You don't have to install Python to try this, but do need Stellarium. There are instructions and links for what you need in the tutorial.

SH4 Celestial Navigation Tutorial

Don,
good job on getting this to work on SH3, I don't have any other versions so it's good to know the savegame files are similar. Take a look at the tutorial, I bet there were times you wished you had a sky as cooperative as Stellarium. I'm almost there. Another 10,000 plots or so and mine will be almost as good as yours.

JBT308 and Pisces,
Welcome to the world of celnav. If you try out the tutorial let me know if it helps understanding, I'm relatively new to this art myself, and getting this working has really helped my understanding of how it works. Don's plots on the previous pages go a long way in explaining some other techniques such as running fixes and proper notation of DR positions on plotsheets. Pisces, just for you I put the time-speed-distance computer on the end of the tutorial. (It's actually a circular slide rule). I was able to write a Python program to generate that directly to pdf.

To all,
Using a Python script to get the sub location out of the game is probably overkill, but I already had it and have used Python for some other projects. It is a powerful and fairly easy to learn free programming language, and there are many tutorials for Python on the web.

Cheers,
Mike

[don1reed]

Well Mike you've got everything bundled into one nice, understandable package. I've taken the liberty of showing off your work over on the SH3 forum, by directing them to this thread and showing how to make it work with SH3 as well.

Excellent piece of work, Mike.

Old Polish Proverb: "A man who catches a big fish does not walk down alleys."

So, step on out into the lime-light my man and take a bow!

(I really like that plot sheet)

[6SJ7GT]

Thanks, Don.
This is one of those projects that is the work of a lot of people. Your knowledge of the art, Thendash's mod to remove the sub marker, Castorps randomisation and my method of taking sightsall coming together into an added touch of realism to the game. Teaches a lot and even makes math fun again as there is a point to all those numbers.

I think everyone can take a bow on this one.

Mike

[jbt308]

Great looking work on the tutorial, now I have something to do at work tomorrow! I've wanted to get into the meat and bones of navigation for quite some time, even toyed with the idea of making my own sextant, but you know how life is. Hell, I bought some slide rules off eBay just because I didn't have a slide rule.

I'm going to catalog for myself, the items you guys have talked about, hopefully if SH4 will comply, we can really get something going that'll work.

As for the Python, I've programmed many simple scripts in the language, and I can tell you it's probably one of the easiest, most powerful scripting languages out currently, though the PERL crowd might beg to differ. Very intuitive, but you do have to have a mind for programming. I'll try and help where I can.

Thanks again all for the hard work.

[6SJ7GT]

JBT308

if you're interested in makinga sextant check out Omar Reis' site, The Xtant Project
I made one of his sextants, there is a pic back on page 7 post #135 of this thread.

Cheers,
Mike

[Pisces]

Originally Posted by 6SJ7GT

....
JBT308 and Pisces,
Welcome to the world of celnav. If you try out the tutorial let me know if it helps understanding, I'm relatively new to this art myself, and getting this working has really helped my understanding of how it works. Don's plots on the previous pages go a long way in explaining some other techniques such as running fixes and proper notation of DR positions on plotsheets. Pisces, just for you I put the time-speed-distance computer on the end of the tutorial. (It's actually a circular slide rule). I was able to write a Python program to generate that directly to pdf.

To all,
Using a Python script to get the sub location out of the game is probably overkill, but I already had it and have used Python for some other projects. It is a powerful and fairly easy to learn free programming language, and there are many tutorials for Python on the web.

Cheers,
Mike

Hmm, when you say it like that it looks like this snake has started to get a grip on me.

[edit] I had look at the time wheel of that slideruler. Great idea for those that don't have one yet. But I suggest changing the intermediate marks to represent steps in 10 minutes, instead of decimals(10ths) of a hour. Seems more natural to me.