Measurement and analysis of multipath by a rough surface reflector using a digital array antenna

A receiving digital array antenna and a rough surface reflector have been used in multipath measurements, whose purpose is to learn more about undesired multipath surface reflections (surface clutter) in radar and how to suppress the reflected signals. The multipath and direct signals were analyzed by Capon power direction-of-arrival spectrum and by the eigenvalues of the spatial correlation matrix. Motion of radar, targets and jammers was simulated by moving the reflector, which also resulted in decorrelation of the multipath signals. The analysis showed that the number of large eigenvalues, and accordingly the required adaptive suppression performance, is dependent on the correlation between the signals and on the number of transmitter signals