Dimitris
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Joined: 7/31/2005
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quote:
ORIGINAL: MarechalJoffre
It is just quick test that you can do in the editor. Put a Burke on one side and two Virginias on the other. Sea state is as I described, Burke is at 20kts and cavitating with active sonar and Virginias are at creep speed. It literally takes 2 minutes to set up. But fine, I'll upload the file.
Here it is. You might point out that subs are showing their broadsides, but even when submarines are facing towards the Burke detection ranges are only down to 7NMI, barely inside the practical torpedo range (keep in mind that the Burke is moving at 20kts still). Kinematic doesn't matter as torpedoes peter out beyond 12NMIs in this build. One other funny thing is how Burke detects the bottom Virginia before the Virginia can get a passive detection. That thing is moving at 20kts!
Okay, let's run the numbers on this example a bit. For clarity's sake, I renamed the eastern sub as Virginia-1 and the western one as Virginia-2.
Local conditions: Heavy rain, 6C degress temperature, Sea State 5. Open sea (local depth 5275m). There is a 50% strong layer between 85 & 146 meters. CZs are forming at 29-58-87-116nm.
The Burke is cruising at 20 knots and cavitating. Virginia-1 is at 5 knots and 122m depth (within the layer). Virginia-2 is at 5 knots and 450m (deep under the layer). Both are beam-on to the Burke.
10:04:18 PM - AN/SQS-53C(V)1 (hull sonar - active mode) on Burke attempts to detect Virginia-1, at 7.14nm. The Virginia has a fairly large active sonar beam-on signature (signature ratio is 0.8). Own-noise modifier is 0.5 (suffers greatly from own-ship noise). No surface ducting. The thermal layer reduces effective range by ~25% (the sub is within the layer). No effect from deep sound channel. No reverberations (deep sea, no ice). No bottom clutter (local depth too great). The sonar has LOS to the sub. Direct-path range in these conditions is 5.68nm. No bottom-bounce possible (too great local depth). No CZs involved. Direct-path limit is less than the actual distance, so the sonar FAILS to detect the sub.
10:04:18 PM - AN/SQS-53C(V)1 (hull sonar - active mode) on Burke attempts to detect Virginia-2, at 7.61nm. The Virginia has a fairly large active sonar beam-on signature (signature ratio is 0.8). Own-noise modifier is 0.5 (suffers greatly from own-ship noise). No surface ducting. The thermal layer reduces effective range by ~49% (the sub is well under the layer). No effect from deep sound channel. No reverberations (deep sea, no ice). No bottom clutter (local depth too great). The sonar has LOS to the sub. Direct-path range in these conditions is 5.11nm. No bottom-bounce possible (too great local depth). No CZs involved. Direct-path limit is less than the actual distance, so the sonar FAILS to detect the sub.
10:04:23 PM - AN/TB-34 (towed array - passive) on Virginia-1 attempts to detect Burke, at 7.11nm. No surface ducting. The thermal layer reduces effective range by ~49% (the sub is inside the layer, but the TA is hanging _under_ it, so it is degraded far more than a hull sonar would). No effect from deep sound channel. No reverberations (deep sea, no ice). No masking factors. No CZs involved. Direct-path range in these conditions is just 2.64nm. The TA has a nominal ~18nm range against the Burke (fairly strong noise source, own-noise negligible), but the severely degraded direct-path limit prevents it from being utilized; the sonar FAILS to detect the ship.
10:04:24 PM - AN/TB-34 (towed array - passive) on Virginia-2 attempts to detect Burke, at 7.57nm. No surface ducting. The thermal layer reduces effective range by ~49% (the sub is well under the layer). No effect from deep sound channel. No reverberations (deep sea, no ice). Direct-path range in these conditions is 5.11nm. The TA has a nominal ~18nm range against the Burke (fairly strong noise source, own-noise negligible), but the degraded direct-path limit prevents it from being utilized; the sonar FAILS to detect the ship.
10:04:26 PM - AN/BQG-5A LWWAA [BSY-2] (flank array - passive) on Virginia-1 attempts to detect Burke, at 7.09nm. The sonar has a nice 24.53nm nominal detection range against the ship (fairly strong noise source, own-noise negligible; if conditions were a bit better it would be able to get a 1st-CZ detection). No surface ducting. The thermal layer reduces effective range by ~25% (the sub is inside the layer). No effect from deep sound channel. No reverberations (deep sea, no ice). No masking factors. No CZs involved. Direct-path range in these conditions is 7.49nm. The sonar has LOS to the ship. Since the target is within both direct-path range and sensor nominal range, the sonar DETECTS the ship successfully.
10:04:26 PM - AN/BQQ-10 (hull sonar - passive) on Virginia-1 attempts to detect Burke, at 7.09nm. The sonar has a 23.3nm nominal detection range against the ship (fairly strong noise source, own-noise negligible; if conditions were a bit better it would be able to get a 1st-CZ detection). No surface ducting. The thermal layer reduces effective range by ~25% (the sub is inside the layer). No effect from deep sound channel. No reverberations (deep sea, no ice). No masking factors. No CZs involved. Direct-path range in these conditions is 7.49nm. The sonar has LOS to the ship. Since the target is within both direct-path range and sensor nominal range, the sonar DETECTS the ship successfully.
10:04:27 PM - TB-37/U MFTA [AN/SQR-20] (towed array - passive) on Burke attempts to detect Virginia-1, at 7.09nm. Nominal detection range against the sub is just 4.2nm (the array avoids the own-noise degradation because it is offboard and under the layer, but the target is very quiet and inside the layer). No surface ducting. The thermal layer reduces effective range by ~25% (the sub is within the layer). No effect from deep sound channel. No reverberations (deep sea, no ice). The sonar has LOS to the sub. No masking factors. No CZs involved. Direct-path range in these conditions is 7.49nm. Since the nominal detection range falls short of the actual target range (and is not boosted by effects such as surface ducting or the DSC), the sonar FAILS to detect the sub.
10:04:27 PM - TB-37/U MFTA [AN/SQR-20] (towed array - passive) on Burke attempts to detect Virginia-1, at 7.55nm. Nominal detection range against the sub is 11.2nm (the array avoids the own-noise degradation because it is offboard and under the layer, but the target is very quiet). No surface ducting. No modification from thermal layer (they are both on the same side of it). The sub is under the DSC, but the array itself is squarely in it, so the practical range is boosted by 50%. No reverberations (deep sea, no ice). The sonar has LOS to the sub. No masking factors. No CZs involved. Direct-path range in these conditions is 14.81nm. Since the target is within both direct-path range and sensor nominal range, the sonar DETECTS the sub successfully.
10:04:28 PM - AN/TB-29 (towed array - passive) on Virginia-1 attempts to detect Burke, at 7.08nm. The sonar has a 23.3nm nominal detection range against the ship (fairly strong noise source, own-noise negligible). No surface ducting. The thermal layer reduces effective range by ~49% (the sub is inside the layer, but the TA is hanging _under_ it, so it is degraded far more than a hull sonar would). No effect from deep sound channel. No reverberations (deep sea, no ice). No masking factors. No CZs involved. Direct-path range in these conditions is 5.11nm. The sonar has LOS to the ship. Since the target is outside direct-path range, the sonar FAILS to detect the ship.
These are just a few of the detection checks happening continuously as the sim runs.
A general observation: You are really not doing your subs any favors by placing them inside the layer or under it. You are repeatedly overlooking a crucial ace that the Burke holds: Its very powerful, very modern towed array. The TA doesn't care about the weather and sea state, and it (mostly) ignores the ship's own noise (it's still affected by its own flow noise though). You need to put a strong layer between it and you if you want to have a (small) chance of getting close enough for a torpedo shot.
A second observation. You complain that subs are detected too easily. Okay. You then substantiate your claim by pitting them against arguably one of the most advanced surface ASW platforms in service, in near-ideal conditions for it (deep water - no reverb or bottom clutter, and your subs on the same side of the layer as its TA). This is like pitting Mike Tyson against Ali in their respective primes and expecting any of the two to walk out of the ring without a scratch. They're both great, and because of this they will both get bloodied.
< Message edited by Dimitris -- 11/3/2020 9:18:01 AM >
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RE: Submarines - Bit too underwhelming? - 
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