Pattern Synthesis for Distributed Space-Based Radar

We describe the leadership of Dr. Hans Steyskal in the study of design principles, performance, and technical risks associated with sparse array radar. As envisioned, the radar consists of a network of small, space satellites that function collaboratively as a highly thinned, distributed array radar for detecting and tracking moving objects near the earth surface. Dr. Steyskal devised an adaptation of processing for ground moving target detection suitable for a periodically thinned, vertical, planar 19-element array that rotates during orbit transit. The array grating lobe array pattern introduces periodic concentrations of ground reflected power in the Doppler frequency power spectrum of the array output. Proper selection of the sampling frequency or radar pulse repetition frequency along with a properly designed cancelling filter at the array output was shown to provide substantial improvement in the ratio of target signal to ground clutter signal at the filter output. The results of an iterative approach for the simultaneous design of the sparse array pattern and post array signal processing are provided along with the effects of array yaw, pitch and positional errors on performance. General displaced phase center signaling and processing for periodic and random arrays are described.