Is this a bug or my misconception? Active Torp acquire range

[KungPao]

I am running some tests on Torpedoes seeker’s effective range. Here is something that get me puzzled.
RA mod 1.50 beta. Somewhere near West African coast, Ocean floor at 13,000ft. Surface duct ocean environment. Below is the SSP profile.


As you can see the layer is at 439ft. I did two tests on how far the MK48 ADCAP can lock the LA Flt III from the head-on direction.

Test 1, sub at 221ft depth, Torp set at 221ft too. Speed set at 50kt (so when it locks the LA, speed increase to 55kts and I would know it has acquired the target). Fire the torp , let it run 2 nmi then make a 180 degree turn. Found out it acquires me at 1050 yds away.

Test 2, sub at 749ft, torp set at the same depth. Same procedure. Found out it acquires me at 390 yds.

I run the tests several times , the results were similar. Torp will get a good lock on me much further in shallow compare in deep . What cause the difference? Based on the SSP profile the sound speed at 221ft is almost same as at 749ft? And I thought Torp should have same acquire range at these two depths?

[p7p8]

In test 2 target was on opposite side of layer

[KungPao]

well, in test 2 the Torp was running and searching at the same side of the layer, (it was set at the same depth as sub, -749ft)

[FPSchazly]

One source of error is the head-on angle of your boat. The game considers the aspect of the target to the seeker head, so a head-on boat has a smaller lock-on target than a beam-on boat. Due to the nature of trigonometry and the angles involved in this problem, if the torpedo is off by just a few degrees in its approach (compass-wise or depth-wise), your boat will look much bigger from the head on approach due to now seeing some of the side or top/bottom of the boat. However, if you do this test from a beam-on perspective, any error in approach angle will be much more forgiving. (To verify, just try looking at some narrow object in real life from the side and from the front and adjust its angle to you a little bit each way to show the effect). However, we're talking no more than maybe a 10% difference here. Obviously, your numbers are much more different than that.



Have you tried the test without the layer? That's just introducing another variable here (that you are correct in thinking shouldn't matter with how you've done the test). I would try without the layer and see what happens.


Also, just to double check, you did these tests at the same layer depth? Layer depth always changes each time you reload a mission.

[KungPao]

Hi FPSchazly
Thank you for your thought on this

Originally Posted by FPSchazly

Also, just to double check, you did these tests at the same layer depth? Layer depth always changes each time you reload a mission.

Yes, I am aware of that. As soon as the scenario begin, I save a file and named it “01, layer 439ft”

Originally Posted by FPSchazly

The game considers the aspect of the target to the seeker head, so a head-on boat has a smaller lock-on target than a beam-on boat.

I am also aware of the signature difference on the front and side. Last week I began to curious , I wanted to know what is acquire range for act/passive Torp on bow/stern/side. Then I begin some tests which eventually leads to this topic.



I made a spreadsheet to record these data, but as you can see it is still very crude. The project stopped right after I started it. Because I realized the depth/sound speed is a variable too. Then after couple testing I noticed that something is not right. It seems the acquire range reduced as the depth increase, no matter what the ocean environment is.

That’s how I started this test, try to see if acquire range is the same at different depth but with same sound speed. I guess I got a "no" answer. But you are right, I should run more test from beam . The reason I choose head on is easy to handle, I just have to make the torp turn 180 degree. After double thinking, I guess I should make sub stop, then a little bit micromanagement I can make the torp come in right at 90 degree.

Originally Posted by FPSchazly

Have you tried the test without the layer? That's just introducing another variable here (that you are correct in thinking shouldn't matter with how you've done the test). I would try without the layer and see what happens.

That’s a good suggestion, I will do more tests latter this week

[KungPao]

Here is what I found

1, Surface duct,




at 221ft, (Sound speed roughly 4723ft/s) Torp locked me at 1.6nm
at 749ft, (4723ft/s) Locked at 1650yds

2, Convergence zone




at 221ft, (4723ft/s) locked at 1.5nm
at 749ft, (4693ft/s) locked at 1750yds


3, Bottom Limit




at 221ft, (4723ft/s) locked at 1150yds
at 749ft, (4731ft/s) locked at 1900yds

[rentacow]

It simply looks to me like your original hypothesis was mostly correct. Based on your data, at whichever depth you do the test, the ADCAP seems to detect you around 1700 yards. To me, this is expected behavior. Sound speed has no effect on the quality of an active return, to my knowledge.

Occasionally some factors may favor the ADCAP, to pick you up beyond a mile, some factors less than 1000 yards. Maybe there are some random elements to the sensors active capability in game? What "Lucky" vs adverse sonar conditions, other than the speed of sound through the water? I couldn't say.