Masterminds..........:doh:

But the whole method of using the frequency ranges at all to alter detection ranges is a matter of simplifying the math... couldn't you get the exact same performance from a sensor responding to 0hz as one responding to freq5 if you set the NRD's to be equivalent?

Luftwolf wrote:
If the dynamic range is great enough I suppose you could create sensors like this, but why would you want to? The idea behind SA's sonar model is that every vessel emits all of it's sound in two discreet frequencies. They happen to be freq3 & freq5.

So let's say there are two vessels, each with a noise output of 75. One has freq3 = 300 and the other has freq3 = 500. The one with a freq3 = 300 will be detected before the other. This is also true in real life. If all sensors were frequency independent, then both vessels would be detected at exactly the same distance.

The flaw in their model occurs if a sensor does not cover either freq3 or freq5. Instead of setting the freq. to 0Hz, they should have used some nominal value such as 1kHz.

cheers, jsteed

I'll make some Excel tables and plots for you, as usually :) they definitely ARE needed to know what range and speed expect in given situation, just didn't know they will be needed so soon. I'll try to make it tomorrow maybe.

Thanx jsteed, that explains a lot :up: Now I have to check my 19k-20k sensor again and see if it works like 0Hz sensor... and if freq absorbtion ranges are calculated not for sensor freq but rather for discrete lines freq, that would explain why I noticed so little and discrete values for freq absorbtion function :D I'll compare it with active sonar also.
And have to write down all the 3rd and 5th freqs from db to see what freq ranges are possible to use...

Lw, I wrote this somwhere already, if you have two sensors, one LF and one MF, then even if you set the nrd value to get same detection distance against one (quiet for example) target, you get (at least should!) quite different det ranges against other (loud) contacts

for example, two sensors:

LF sonar, nrd set for 1nm against Akula 2, then 25nm against supertanker
MF sonar, nrd set for 1nm against Akula 2, then 10nm against supertanker

the difference in DW sonar model is maybe little smaller, but you can see it clearly on this example.

Ah gotcha. :|\\

I'll work on this some more once the torpedoes are done (holding the design in my wetware is taking up system resources :88) ).

Cheers,
David

PS In fact, this comes just in time FOR the torpedoes themselves. Thanks for this data... I'll find out what I can do with it very shortly. :up:

Does that mean that the equations I posted are wrong????

They are most probably correct :up: (I didn't checked them) but the nice graph is speaking to me better than equations, so I though it will be helpfull anyway :)

I actually find numeric tables to be better for that sort of thing. I made one using speed and depth input into those equations to get a range result. =) It will soon have a place right next to my NL tables. :up:

So check your equations if they are consistent with those thables and graphs (I'll take a look at them myself too hm I'm putting them into my spreadsheets to see if I get correct results ).

So, I had something like that on my mind:


Most important parameters of all new torpedos:
http://img184.imageshack.us/img184/5...edostable1.png

(note: the standard long range mode is 40kts (passive speed) for ADCAP and 35kts for UGST. But you may note that minimum speed is listed as 30kts for ADCAP and 25kts for UGST, and running torpedo that slow will give you some extra range even outside 27nm. And it's all you can get, because torpedo will not slow down below it's minimum speed (if you set 10kts for example you still get 30kts) so it's absolute maximum range of weapon in the mod - about 31nm/30kts for ADCAP and 35nm/25kts (maybe this will be limited by db value as it's little long) for UGST. Anyway very slow run can give you more endurance (loiter time) or time to move away from launch point without spending much of torpedo fuel, then when ready you can speed up torp by enabling it. In real life VERY low torpedo speeds (in 10-15kts range IIRC) results in longer run but suprisingly smaller torpedo range, because torpedo (having negative buoyancy) runs at high angles of attack which increases drag and decreases speed and fuel effectiveness... and many torpedos simply don't have such low speed settings, engines were designed usually for two or three fixed speed settings only.)



Below table and graphs are valid ONLY if playtest one version of torpedos uses the parameters shown above ! LW if you have changed something in torpedo parameters, tell me I'll make another graphs (and send you spreadsheets to make them too).

Speed and range at various depths for ADCAP and UGST:

http://img306.imageshack.us/img306/6...edostable2.png

ADCAP - graph shows how the speed and range decreases with depth for two speed settings - 55kts and 40kts. But for other settings speed decreases with depth in the same way - linear.

http://img306.imageshack.us/img306/1...edosgrapha.png


Same for UGST - speed and range decrease with depth

http://img306.imageshack.us/img306/9...edosgraphu.png


P.S. If "autothrottle" of depth compensation feature is added, the graphs would look quite different... something like that:

(thin line is current performance, thick lines are what would be - as you see for max speed nothing changes, for 40kts setting you get more speed at depth but at cost of much greater fuel usage so shorter range - near max depth the engine is working at max so range is same like for 55kts setting).

http://img288.imageshack.us/img288/1...edosgrapha.png

P.S. I have to think about deep passive torpedos (are they going to happen?) - the speed can be controlled by throttle setting like now (without adjustment which eats range), but what should be done is adjusting the PASSIVE ENABLE LIMIT (of 40kts) to be "40kts of true speed" and not "throttle for 40kts" as currently.

Note that to get exact range for variable speed and/or depth torpedo run, you would have to calculate fuel usage for each portion of run at different speed and depth. Just like a plane that covers some distance at medium speed at low altitude, then cruises at high, then returns back to low alt and during the flight thrust was also changed few times from cruise to military and afterburner... each part has different fuel usage, and it's not easy to calculate this on paper...

Seems they are OK :up: