An alternate analysis for the second-order high frequency bistatic radar cross section of the ocean surface - patch scatter and its inversion

In this paper, the verification of the second-order high frequency (HF) ocean surface cross section for a surface patch remote from the transmitter and receiver is presented. The bistatic result is shown to reduce to the proper monstatic models when the appropriate geometry for backscatter is introduced. In particular, the electromagnetic coupling coefficient for the bistatic case is seen to incorporate its monostatic counterpart. It is well-known that the second order portion of the HF radar spectrum of the ocean echo contains substantial information on the surface gravity wave spectrum. Thus, the initial analysis forms the basis for the extraction of ocean surface parameters from bistatic HF radar data. An inversion technique for extraction of ocean surface wave parameters from bistatic HF radar data is briefly developed here. The inversion results from simulated spectra are seen to be very reasonable.