SBR waveform and processing parameters as a function of array distortion

Structural distortions in large antennas have impact on antenna gain, sidelobe level and adaptive interference rejection. Partial compensation for the distortion of space-based radar (SBR) phased-array antennas and array-fed reflectors can be achieved by adjusting the phase-shifter settings to compensate for the distortion, if it can be accurately measured. This approach is effective in regaining the antenna gain and sidelobe levels, but the adaptive rejection of interference and clutter is much more complex. This paper addresses the ground moving target indication (GMTI) performance for a large active electronically scanned array (AESA) at a medium-earth orbit (MEO) altitude of 10,000 km, and a maximum sinusoidal mechanical distortion of 10 cm modeled across the horizontal aperture. To evaluate the impact of mechanical distortion on GMTI performance, the full-dimension space-time adaptive processing (STAP) matched filter (MF) and the reduced-dimension joint-domain localized (JDL) algorithms were evaluated using signal-to-interference-plus-noise ratio (SINR), SINR loss and minimum discernable velocity (MDV) as the GMTI performance metrics