ELECTRONIC PROTECTION (EP) FOR ELECTRONICALLY STEERED ANTENNAS (ESAs)

"Distributed aperture approaches for future, space-based C3ISR systems, such as the AFRL/VS TechSat 21, have significant advantages over current monolithic designs. While several signal-processing approaches are being developed to exploit the spatial andwaveform diversity offered by a distributed aperture, the performance sensitivity of these algorithms has not been demonstrated under varying degrees of channel coherence, relative metrology and timing precision, and clutter environment realism. Thetesting of sparse aperture signal processing algorithms under controlled and variable conditions is critical to ensure the viability of operational concepts, robustness of space subsystems, and performance of distributed aperture architectures. Amulti-channel airborne surrogate with movable apertures will be used to provide a low-cost means of collecting data for algorithm test and evaluation. The data collections will be thoroughly planned to provide sets of SAR and GMTI range/Doppler maps thatcan be used by researchers to validate a variety of distributed aperture approaches well in advance of planned on-orbit experiments. The data sets will be used to validate several emerging signal processing concepts, including: multi-channel SAR imaging,multi-channel GMTI imaging, along-track displaced-phase center antenna processing, and SAR electronic protection. The signal processing techniques to be developed have immediate application to both nex