Reciprocal path scattering from surfaces and turbulence in monostatic ladar theory

We present a modification to the laser radar equation (LRE) which includes the combined first-order effects of rough surface (RPS) and double passage (DP) RPS. A thin random phase screen atmospheric turbulence model is first included in the LRE. Rough surface RPS and DP- RPS are included individually, then we present the reciprocal path modified LRE (RPMLRE) for the combination of the two processes. The RPMLRE is formulated such that the predicted diffuse and coherent received power components are easily extracted from the total received power. Calculations are presented for a 1.064 micrometers ladar operating against a 1 m2 space target. A substantially increased received power is predicted by the RPMLRE over that predicted by the LRE including turbulence only.