[REQ] Map elevation data ?

[vanjast]

A couple of questions :-

1) Does anybody know where the map elevation data is kept(and its associated objects and textures), within the SH4(3) files.
2) Any idea of what format this data is stored in.

I'm going to do some mapping wrt WW2 period of our local coastline, so would like to mod it a bit.

Any ideas..

Thanks
Van