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Game engine ignores such values for the UUV. I left it as it was for reference.
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I'm surprised. It's possible to change UUV sensor sensivity, but impossible to change frequency range ? Have to try it myself... right now, I'll set it to 1100-1200Hz and see if it reduces det ranges.
The mission I run, was simply Capitallists vs communists - there is Rubis at 7kts (non cav) which was detected by UUV right out of the tube from 20nm...
edit: I changed UUV sensor freq range to 1100-1200Hz and in the same mission it didn't detect anything (but me), and there were two cavitating Akulas and Type-206 10nm from me. Now reverting to 0-1200Hz...
Cavitating Type-206 detected from 28nm, Rubis 7kts from 15nm, many other contacts, just after leaving tube.
Yeah I know should test same scenario, but from above seems that what is set in frequency limits is making difference in UUV performance.
Now changing to 1200-12000 range...
OK, I have setup with some close targets, Rubis 7kts at 10nm. Launching UUV... didn't detect it. It even didn't detect a close freighter from 6nm !!!
LW, db freq range definitely works for UUV sensor for me. At least this is what I can conclude from above. Two times nothing detected with high freq limit (1100-1200 and 1200-12000), lots of targets, even far away, detected with stock 0-1200 freq limit.
P.S. Cross layer trawler not detected at 5nm, detected at 3.6nm, 1200-12000Hz freq limit. At what range is 8kts trawler detected by 0-2000Hz UUV sensor ? Freighters were even at 10-15nm if not longer...
P.S. Now, when I believe that frequency range is in fact working, I'll try to use DWAnalyzer to give some results for comparison. As long as there is no layers involved, DWAnalyzer sonar model is still very good.
Sea state 1, convergence (but above layer, target and sensor both at 60m/200ft, rock bottom, DWAnalyzer results, all tests on LwAmi302 database
Playtest One UUV, +7 sensivity, 0-1200Hz freq range
Akula II 10kts 180 meters
Akula II 5kts 12m
Kilo Imp 5kts 9m
Kilo Imp 0kts 5m
Rubis 7kts 300m (very strange, maybe mine was CZ contact ?? anyway it is detected by UUV from 10-15nm in every my test in CvC scenario)
Han 5kts 6500m
Han 10kts 12130m
Trawler 5kts 6700m
Cargo Ship 10kts 24000m
Cargo Ship cav 33000m
Supertanker 15kts 29000m
Car Carrier cav (most noisy sound in db) 43000m
so loud targets are detected from far ranges
Now +7, 1200-12000Hz sensor:
Akula II 10kts 10m
Akula II 5kts 4.8m
Kilo Imp 5kts 3.7m
Kilo Imp 0kts 2m
Rubis 7kts 213m
Han 5kts 1922m
Han 10kts 4630m
Trawler 5kts 2333m
Cargo Ship 10kts 10133m
Cargo Ship cav 16300m
Supertanker 15kts 12133m
Car Carrier cav (most noisy sound in db) 21850m
Now +7, 3000-12000Hz sensor:
Akula II 10kts 9.6m
Kilo Imp 5kts 3.9m
Rubis 7kts 212m
Han 5kts 1922m
Han 10kts 4024m
Trawler 5kts 2012m
Supertanker 15kts 12074m
Car Carrier cavitating 19230m
Now for comparison -3 (!!!), 3000-12000Hz sensor:
Akula II 10kts 250m
Kilo Imp 5kts 200m
Rubis 7kts 1920m
Han 5kts 6700m
Han 10kts 9400m
Trawler 5kts 7300m
Supertanker 15kts 18100m
Car Carrier cavitating 25500m
results for stock db -3, 0-1200Hz UUV seeker - later
P.S.
Hm, found something really interesting. I couldn't further decrease detection ranges by increasing freq limit over 3000Hz, even for 20000Hz ranges were the same. So I checked how frequency absorbtion values (visible in DWAnalyser) are looking for different frequencies. And I'm little disappointed.... Seems there is no frequency absorbtion function, only four discrete bands with fixed freq absorbtion coefficient value for each...
Results of freq. absorbtion for passive sonar at 50000m:
Hz 50km 1m (min value)
0 38 4
20 38 4
40 38 4
49 38 4
50 38 6
59 38 6
60 55 6
80 55 6
100 55 6
300 55 6
500 55 6
800 55 6
900 55 6
909 55 6
910 71 8
1000 71 8
1200 71 8
1300 71 8
1400 71 8
1477 71 8
1478 81 8
1480 81 8
1500 81 8
2000 81 8
3000 81 8
5000 81 8
8000 81 8
12000 81 8
20000 81 8
edit: I wonder if this changes with depth or conditions... maybe another time... no, checked this - at least in DWAnalyser water depth doesn't change frequency absorbtion value. So that's why in very shallow water we can get better propagation than on deep water !!!! (narrow sound channel, yes, but I believe in RL multiple bottom bounces should weaken and disperse the sound quickly, and the very low frequency sound waves maybe can't propagate at all when the sound channel is smaller than sound wave length ??). So that would be next thing to ask Sonalysts for - after discussing it with our experts here - to make frequency absorbtion value depending also on water depth and bottom type.
As can be seen, there are only 4 different values for whole range 0-20000Hz... Freq bands would look something like that:
0 - 59Hz 1 or 1.52dB/km
60 - 909Hz 1.45 or 2.2dB/km
910 - 1477Hz 1.87 or 2.84dB/km
1478 - 20000Hz 2.13 or 3.24dB/km
little strange... comparing this to this graph:
on the graph in 1000-10000Hz range, freq absorbtion changes 100x !! At 10kHz it's one dB for 1000m, at 1kHz it's only one dB for 100.000m. Is that graph good ?
And we have... one freq. absorbtion value for this band !!! Any thoughts ??
According to the graph, between 100Hz and 1kHz real frequency absorbtion in water increases about 100 times. 100 times (in dB already - because coefficient value is in dB/m). In DW seems that between 100Hz and 1kHz there is difference of only about 1.44-1.87 times...
What's up ?
In original DB there are values 100, 300 and 800Hz used. From data above it would seem that 100 and 800Hz are valid but 300Hz would not make any difference as it comes into same band as 800Hz... This has to be checked in gameplay tests - is there is ANY difference between 300 and 800Hz sensor...? BTW the minimum possible (at 1-100m distance) frequency absorbtion values are greater than zero (-4 at 0Hz to -8 above 1000Hz) and this value has only 3 freq bands... How there can be frequency absorbtion loss of 4 to 8 game dBs (8 to 16 real life dBs) at 1 meter distance ??? All this is little complicated, I'm far from understanding fully how this works in DW :-/.
So in fact there are only 4 sonar "performance" bands, depending on sonar min frequency value. Anything higher than 1500Hz doesn't make any difference. I would suggest to set UUV sensor min. frequency to 1500Hz to get the last, higher frequency absorbtion.
P.S. While searching for frequency absorbtion graphs on the web, i've found this:
http://www.npmoc.navy.mil/KBay/oceano.htm
Absolutely fantastic site with lot's of sound propagation examples and info !!