How does the seabed affect sonar? - devs need help

[Destraex]

http://forum.paradoxplaza.com/forum/...d-affect-sonar

"How does the seabed affect sonar?
Ok, we've collected a lot of resources on various aspects of naval warfare over the years, as I am sure you can imagine, but I can't find a good explanation of how to model how sonar affects detection near the seabed.

What's the best way to model the effect on detectability when the sub is near the seabed (the ocean is relatively shallow)? Conversely, how does this affect the sub's own active and passive sonar when it tries to detect surface targets? What if it is near an edge, where it gets deeper, or a steep, where it gets more shallow.

NWAC is not a sub sim per se, but these things should be modeled as accurately as possible (within reason).

Since this is such a knowledgeable forum, I'd like to have your feedback if possible."

[magicstix]

Mostly the bottom acts like a mirror or a sponge for sound, depending on what it's made of. Highly absorbent bottoms like mud result in sound not bouncing, whereas reflective bottoms like rock lead to farther propagation through bottom bounce. The roughness of the bottom also has an effect in that it causes scattering, which makes the reflected sound less specular.

The surface of the ocean acts the same way, but it's more or less a "perfect reflector." However, bubbles and facets from wave action give the surface a sort of "crumpled aluminium foil" reflectivity, much like a photographer's light dispersing mirrors. The bubbles also lead to absorption, making the surface less perfect of a reflector.

[Micksp]

If you need any help, info, etc. feel free to contact me any time.