Distributed apertures for robustness in radar and communications (DARRC)

Two robust techniques that utilize spatially diverse distributed apertures are presented. The first technique is used for improved electromagnetic interference rejection for both radar and communications systems. The second is for improved detection of over resolved targets for multiple-input multiple-output (MIMO) radar systems. For the former, experimental data was collected and adaptively processed using sample matrix inversion (SMI) for a scenario where a target vehicle traveled along a course that brought it past an interference source. Post cancellation SNR of target detection with respect to electromagnetic interference (EMI) was improved. The proposed MIMO radar configuration can be employed jointly to radar and communications systems sharing the same spectrum to improve isolation between them. For the latter technique we have demonstrated the potential of orthogonal waveforms in distributed aperture radar architectures (DAR) for achieving improved resolution, interference suppression, and target detection and tracking performance while simultaneously controlling space-frequency grating lobes. Adaptive processing using frequency diversity was simulated and demonstrated. A knowledge-aided algorithm was employed to estimate the covariance matrix needed for the adaptive processing algorithm. Experimental data was collected to successfully demonstrate an improvement in radar imaging capability by using data from both radars compared to mono-static data from single radar.