A ML multichannel ATI-SAR technique for measuring ocean surface velocities

Conventional along-track interferometric (ATI) synthetic aperture radars (SAR) derive the ocean surface velocity from an estimate of the phase difference between the SAR processed echoes received from two displaced phase centres with a single time-lag. A maximum likelihood (ML) algorithm is proposed to process the multi-channel SAR data from an array of phase centres with multiple time-lags. The new technique provides sensibly better estimation accuracy than the conventional one. Moreover, it provides unambiguous velocity retrieval and flexibility to ocean coherence time.