Adaptive Signal Processing to Counter Jamming

Electronic counter-countermeasure (ECCM) techniques, such as adaptive beamforming (ABF), allow RF sensors to operate in hostile jamming environments. As today’s radar imaging and target identification methods require increasing bandwidths, ECCM techniques must become robust over these large bandwidth intervals. We propose to develop, under this SBIR program, a wideband ABF algorithm suitable for high-resolution imaging and target identification techniques. To accomplish this, our algorithm utilizes time-delay steered subarrays where the subarrays are adaptively combined in the frequency domain after the time-delays have been applied. True time-delay (as opposed to phase) pre-steering produces beams that are consistent over large bandwidths. Furthermore, to ensure smoothly varying adaptively weighted subarrays over frequency, derivative based updating (DBU) is employed. The result is a wideband ABF algorithm that will be robust to large bandwidths for narrow and wideband jamming with good spectral preservation of the signals of interest.