Questions about sonar models inert

[Rhialto2]

In CMANO what factors are taken into account when one submarine is trying to detect another by passive sonar?

I know that bearing of target is modeled with dead spots astern - in the baffles. However, does it make a difference if the sub to be detected is head on or side on? Does the bulk of the submarine hide the noise of the prop?

So if I have an enemy submarine detected on passive sonar and I want to not be detected in return while waiting for a firing solution, what actions can I take that will make a difference in this game?
Come to dead stop-is this better than creep?
Depth just above layer? Hiding in layer may be stealthier but reduce my own passive sonar range?
Turn to an attitude that reduces my own cross section? Or does this only factor into active sonar?

Also, where in the DB entry does it tell me the acoustic size (noisiness) of the submarine? I looked and didn't see it. Without this, how can I tell if an Astute class is quieter than a Virginia class or not?

[Rhialto2]

No answers? OK let's try this again.

1. Where can one find the value for how easily a given submarine type can be detected by passive (due to its power plant noise emissions) and by active (cross-section, acoustic tiles) sonar?

2. Other than throttle speed and depth, can one do anything to alter this (e.g. attitude to target)?

[SerenitySteele]

I probably wont be much help, but here goes.

If I detect a submerged contact, I stick around until I figure out what direction it's going. Then I put the layer between me and the contact and pick up the speed a little bit. Once I cover however much distance I think is sufficient or safe, I slow down, clear my baffles, then back to the same side of the layer that I picked up the contact. Rinse and repeat until I get enough information to get into a good firing position. This is pretty much the same tactic I use in Silent Hunter 3 GWX, only sensor quality was much lower back then and diesel/electrics are usually quieter than modern subs.

Target angle/AOB/attitude has an insignificant impact on your signature with passive sonar. Really only matters with active sonar where a full on broadside would obviously return a stronger signal than from 0 or 180 degrees relative bearing.

For detection values for passive sonar, it's the first four rows under "Signatures" in the database for the platform in question: VLF, LF, MF, HF. The lower the dB, the quieter you are and thus harder to detect. For the Astute vs. Virginia, I just glanced it over, but they look to be about the same.