Seeing the SSP in action?

FERdeBOER · 11-12-07, 07:40 AM

Quote:

Originally Posted by Sonoboy

Just the other day, I was experimenting with depth below the layer and detection ranges with a surface duct. I had contacts spread out from 1nm up to 18nm. I made a graph of it in excel, and I will post a screenshot of it when I can.

Does anyone know of a good place that will host the image?

Sounds very interesting.
How did you make that?

Imageshack http://imageshack.us/ is a good place to upload a screenshot.

Sonoboy · 11-12-07, 08:05 PM

I had 18 Nimitz spread out evenly along 180 degrees to my front, since I was using the sphere array for this experiment. They were successively spaced in intervals of 1nm starting at 1nm from ownship. All speeds were at 15kts. I simply changed depth under the layer until I was able to hear a contact, then find the exact depth at which contact was gained. I recorded 3 trials, each with a different layer depth. The graph below also has trendlines included. I would assume that layer depth in this experiment would also equal contact's altitude above the layer (I havent tested with submarines yet).

http://img228.imageshack.us/my.php?image=layergk9.jpg

The shadow zone would be to the right of the curve, and the detection zone to the left.

Molon Labe · 11-12-07, 10:31 PM

Quote:

Originally Posted by Sonoboy

I had 18 Nimitz spread out evenly along 180 degrees to my front, since I was using the sphere array for this experiment. They were successively spaced in intervals of 1nm starting at 1nm from ownship. All speeds were at 15kts. I simply changed depth under the layer until I was able to hear a contact, then find the exact depth at which contact was gained. I recorded 3 trials, each with a different layer depth. The graph below also has trendlines included. I would assume that layer depth in this experiment would also equal contact's altitude above the layer (I havent tested with submarines yet).

http://img228.imageshack.us/my.php?image=layergk9.jpg

The shadow zone would be to the right of the curve, and the detection zone to the left.

Was the SSP for that data Surface Duct or Convergenze Zone?

Sonoboy · 11-12-07, 10:34 PM

Quote:

Originally Posted by Molon Labe

Was the SSP for that data Surface Duct or Convergenze Zone?

Surface duct.

Dr.Sid · 11-13-07, 04:13 AM

Nice one

Would be good to add even more shallow layers with CZ SSP. And to test if there is any difference in shadow zone shape with CZ SSP.

FERdeBOER · 03-16-08, 05:22 PM

Sorry for refloating this post. I come from this one http://www.subsim.com/radioroom/showthread.php?t=131383 but I think this is a better place to talk about what I've made.

I've been making tests with this:
- O.H. Perry in ENCOM at 10 knots closing to an Akula2 (me) running at 5 knots.
- Seastate 2
- Surface duct, very deep water
- April, mid Atlantic (30N), clear weather
- LwAmi mod v3.08
- SONAR autocrew
- Created a trigger that tells me when I'm detected by the Perry.

These are my first results:

when I'm at 500m deep, I detected the Perry very far (more than 14nm if I remember well) and I was detected at 5 nm.

When just up or bellow the layer I was detected at 8,5 miles and I still not detected the Perry.

At 50 meters I detect the Perry at more than 10 miles (don't remember exactly) an was detected at 8 miles.

At PD I detect the Perry at 14 nm and was detected at 7,5

So I'm comfused

- seems that you're right about ownship's detection capability and shadow zones. But I allways thought that if you're in a shadow zone and you can't detect a ship, the ship can't detect you... but my tests doesn't support this...

- Some players, like Dr.Sid, have stated that approaching just bellow the layer is a very good tactic, even better than doing it deep... but again my tests says that going deeper is better.

I have to test this with suonobuoys under and above the layer, but seems that against a surface ship in deep waters is better going as deep as you can...

My next tests will be with excel open...

EDIT: OK, I've made a new test with conditions changed a bit:
- Instead of my sub being the one detected by the Perry, I set up a line of 12 Akula2 AI subs at 5 knots a different depths and triggers that tell me when a sub is detected by the Perry.
Conclusion: you're right and I was wrong.

The detection depth is more or less the same above the layer (8 miles), but just below the layer it decreases highly to 3.6 miles and, as we go deeper, the range increases again to 7.8 miles at 500 meters.

I will make another test tomorrow, this time also with the subs detection range and will post some screens.
But seems you're right, being just above the layer is a great chance for the sub.

Molon Labe · 03-16-08, 09:14 PM

Quote:

I've been making tests with this:
- O.H. Perry in ENCOM at 10 knots closing to an Akula2 (me) running at 5 knots.
- Seastate 2
- Surface duct, very deep water
- April, mid Atlantic (30N), clear weather
- LwAmi mod v3.08
- SONAR autocrew
- Created a trigger that tells me when I'm detected by the Perry.

Quote:

- seems that you're right about ownship's detection capability and shadow zones. But I allways thought that if you're in a shadow zone and you can't detect a ship, the ship can't detect you... but my tests doesn't support this...

If you are using sonar autocrew, you cannot say with any confidence that you were in the shadow zone but were counterdetected anyway. In all likelihood, you were NOT in the shadow zone and you both could have detected each other.

Quote:

- Some players, like Dr.Sid, have stated that approaching just bellow the layer is a very good tactic, even better than doing it deep... but again my tests says that going deeper is better.

I have to test this with suonobuoys under and above the layer, but seems that against a surface ship in deep waters is better going as deep as you can...

There are no 'good tactics' in the abstract. Tactics are goal-dependent. If holding a track is more important that avoiding counterdetection, then deeper is better. If avoiding counterdetection is more important than holding a track, than shallower is better.

Quote:

EDIT: OK, I've made a new test with conditions changed a bit:
- Instead of my sub being the one detected by the Perry, I set up a line of 12 Akula2 AI subs at 5 knots a different depths and triggers that tell me when a sub is detected by the Perry.

...a much better method of testing.

11-12-07, 08:05 PM	#2
Sonoboy Planesman Join Date: Aug 2005 Location: United States, CA Posts: 195 Downloads: 9 Uploads: 0	I had 18 Nimitz spread out evenly along 180 degrees to my front, since I was using the sphere array for this experiment. They were successively spaced in intervals of 1nm starting at 1nm from ownship. All speeds were at 15kts. I simply changed depth under the layer until I was able to hear a contact, then find the exact depth at which contact was gained. I recorded 3 trials, each with a different layer depth. The graph below also has trendlines included. I would assume that layer depth in this experiment would also equal contact's altitude above the layer (I havent tested with submarines yet). http://img228.imageshack.us/my.php?image=layergk9.jpg The shadow zone would be to the right of the curve, and the detection zone to the left. Last edited by Sonoboy; 11-12-07 at 08:17 PM.

03-16-08, 05:22 PM	#6
FERdeBOER XO Join Date: Mar 2002 Location: Spain Posts: 431 Downloads: 22 Uploads: 1	Sorry for refloating this post. I come from this one http://www.subsim.com/radioroom/showthread.php?t=131383 but I think this is a better place to talk about what I've made. I've been making tests with this: - O.H. Perry in ENCOM at 10 knots closing to an Akula2 (me) running at 5 knots. - Seastate 2 - Surface duct, very deep water - April, mid Atlantic (30N), clear weather - LwAmi mod v3.08 - SONAR autocrew - Created a trigger that tells me when I'm detected by the Perry. These are my first results: when I'm at 500m deep, I detected the Perry very far (more than 14nm if I remember well) and I was detected at 5 nm. When just up or bellow the layer I was detected at 8,5 miles and I still not detected the Perry. At 50 meters I detect the Perry at more than 10 miles (don't remember exactly) an was detected at 8 miles. At PD I detect the Perry at 14 nm and was detected at 7,5 So I'm comfused - seems that you're right about ownship's detection capability and shadow zones. But I allways thought that if you're in a shadow zone and you can't detect a ship, the ship can't detect you... but my tests doesn't support this... - Some players, like Dr.Sid, have stated that approaching just bellow the layer is a very good tactic, even better than doing it deep... but again my tests says that going deeper is better. I have to test this with suonobuoys under and above the layer, but seems that against a surface ship in deep waters is better going as deep as you can... My next tests will be with excel open... EDIT: OK, I've made a new test with conditions changed a bit: - Instead of my sub being the one detected by the Perry, I set up a line of 12 Akula2 AI subs at 5 knots a different depths and triggers that tell me when a sub is detected by the Perry. Conclusion: you're right and I was wrong. The detection depth is more or less the same above the layer (8 miles), but just below the layer it decreases highly to 3.6 miles and, as we go deeper, the range increases again to 7.8 miles at 500 meters. I will make another test tomorrow, this time also with the subs detection range and will post some screens. But seems you're right, being just above the layer is a great chance for the sub. __________________ Hay dos tipos de buques: los submarinos... y los blancos. There are two types of ships: the subs... and the targets. Last edited by FERdeBOER; 03-16-08 at 07:12 PM.

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11-13-07, 04:13 AM	#5
Dr.Sid The Old Man Join Date: May 2005 Location: Czech Republic Posts: 1,458 Downloads: 6 Uploads: 0	Nice one Would be good to add even more shallow layers with CZ SSP. And to test if there is any difference in shadow zone shape with CZ SSP.