I was talking about DW
Real sea is even more complicated than that !
you don't have bathymetric areas on your map IRL
It's close to be a cheat in fact ................
lets say it simulate a superior bathymetry assistant, just getting out of 15 years of school, and able to calculate where are the best SNR areas around ....
Hmmm, I don't even convince myself with that argument ... hmmm :hmm:

As for the "swapping" of the map over at the CADC please read my comments there ...

http://www.orionwarrior.com/forum/sh...ad.php?t=30183

In short, if this map was swapped then it was by either me or Swimsalot and I certainly did not do it (and it is in doubt if it was swapped at all ... see comments).

OS - Yep I posted at CADC.

It looks as if it was another result of the LwAmi install which got screwed on Saturday giving odd Playtest UUV results.

**Sorry, it looks as if the second scenario file I downloaded was corrupted. ( how :hmm: )

**So my original findings stand (See below)

** Edited 24 th.

In my opinion the game changes the SSP everytime you enter the map, just a litle. So the outcome could be totally different.

Yes, that's the reason that whenever possible (no database changes) I did tests not starting a scenario multiple times, but starting it once and then restoring from save multiple times.

Between 'executing' headshots in GRAW I have revisited this matter and my original findings stand as it was the second downloaded file that became corrupted. The one tested is the one at CADC.

Fish: Screenies of several dives show that the on- board ISP indicator in sonar shows widely different ISPs
and layers from each subs perspective. The Nav screens dumps of the simplistic (Sh+I) did not change ( as expected !)

What Swims asked, and I dont think anyone has answered fully, was what contributed to this wide range of
sonar fluctuations and the disappearing tonals. It should be noted that in this scenario the ISP & layer conditions vary dramaticaly and the topography makes a large contribution to these effects.

You start positon in the CAD map is shallow, when you change depth shortly after start, which many people do, me for example after looking at the SSP indication window, you should see a great differents in detection range. Maybe they changed there depth? :-?

About OKO's dark and light area's I doubth he is right there in his explanation.
When he first came with the idea the dark spots are hotspots for listening I did numerous test, but could not find prove.
On the other side, you could prove the opposite as shown in the pics below.

First a Seawolf listening at a worse place (light).



http://home.hccnet.nl/wico.p/Detection4.JPG


I was able to assign a tracker on a faint 60 hrz line.


http://home.hccnet.nl/wico.p/Detection3.JPG

Now the other seawolf at the "right"place (Dark)

http://home.hccnet.nl/wico.p/Detection1.JPG

Nothing, not a blip!

http://home.hccnet.nl/wico.p/Detection2.JPG

Fish: I agree the subs in my dives which established contacts at over 20 nm were in the bright areas. As a matter of fact the contacts were in bright areas also (just). Almost looks like a simple mathematical progression. (But why ?)

The Ak is situated well inside a large 'bright' area whilst ths SWs are near the edge of 'dark' areas and its likely the divers progressed into them.

XBT readings taken shortly did'nt differ from the startng ones, as usual, but were taken at or near the opening depth.

There's a possibility of topographical noise stripping there, as 60hz is right in the sweet spot of distant shipping on a Wenz curve. The depths look plenty deep for CZ propagation, too. But again like I said earlier, I don't know what the ambient noise modelling is like in the game (I would suspect it's based on Wenz curves though).

In other words, the sub in the shallower water is seeing ambient noise from distant shipping stripped off, while the sub in deeper water is still seeing it, so the signal to noise for him is significantly poorer.

In other words I don't think that upslope/downslope propagation, like you guys are postulating, is particularly relevant here. The water is quite deep, whereas that phenomenon is more likely to occur in slope/shelf areas as far as I can recall.

CC: 'Sloping/shelf' is what we have here with a focal point at 100 ft and the sea bottom valley gently sloping down to 3500 ft. Its like half of a cone with the Ak at the point. That must surely contribute to some 'amplification' effect.

This initial 'amplification' effect will be negated by the SW to the North diving (probably) behind the seamount to its South. Also both the SWs sit at the edge of changing receptivity as shown by the Nav area shading simplification.

A fascinating location with some pretty interesting potential exploits. The scenario designer made a skilful choice. :|\

Interesting.

I'm glad the shadow zones are working now. :up:

Ok, note to self: go to the light.

I'm not sure the analysis is as complicated as some are making it out to be.

:lol: But ''interesting'' still. ;)

Wow, great info guys, thank you for the help.
There must be more variables involved than I suspected, which is why I didn't think it was a cheat, just a curiousity.
Has anyone confirmed the info about "light" areas vs "dark" areas in terms of sonar detection ranges?

What's the bottom type? Smooth rock? What kind of bottom loss modelling is employed? This sort of stuff is very important.

Because to get the upslope/downslope focusing/megaphone effect you need to have at least reasonable bottom bounce conditions. But 10-15kft is very deep for more than one or two bottom bounce annuluses (annuli?), whereas true upslope/downslope tends to take place in much shallower water - the slope/shelf I was referring to was the continental one.

Moreover, downslope is more effective by far, whereas in the screenshots it's the sub upslope having better success, which in my opinion points to a TNS situation. Although at ~11 miles, I think the detection path was surface duct (much too short for CZ).

Without some sort of game-related range prediction program, or knowing how the game handles various factors (noise level, bottom composition, etc), all we're doing here is making guesses.

And, something just occured to me as I was about to hit submit:

The sub in deeper water may just be missing the downslope enhacement by virtue of being quite shallow, whereas the sub in the shallower water could be picking up the upslope effect given a bottom type with low loss characteristics. Intermittent contact would sort of point to that situation.

ASW is fun :|\

I'd like OKO to explain how he came by his conclusion.

It is interesting as I had heard it before. I can't recall Jamie saying anything though.