None.

To find the stationary column, use GM (Ground mapping).
If they move, use GMT (Ground Moving Target).
Once found, slave TGP to the area and start moving mud - radar isn't really important from here on.
Good trick is to put mark-points on each side a stationary column, then switch those steerpoints slaving the TGP for a good view.
Just don't go below 12000ft and get beaten up like I too often do.