Tactical Counter Concealment Aerial Sensors Electronic Protection (TC-CAS EP)

Low-frequency synthetic aperture radars (SARs), which tend to have very broad antenna beams and relatively small waveform bandwidths, are inherently vulnerable to unintentional RFI and to intentional electronic attack (EA). EA is typically performed using either: 1) a barrage noise or swept spot noise jammer or 2) a coherent DRFM repeater. The interference or jamming signals can enter the SAR through its mainlobe, sidelobes and/or backlobes. No single electronic protection (EP) technique is sufficient to address all of these interference and deception sources. Therefore TSC will investigate a variety of EP approaches that include: 1) the use of multiple phase center antenna array processing including both an algebraic solution for the antenna pattern adaptation and an adaptive singular value decomposition (SVD) approach for post-processing image enhancement, 2) robust SAR waveforms and mismatched pulse compression filters, and 3) adaptive antenna polarization agility. Two or more of these techniques can be simultaneously applied to address the RFI / EA scenario. TSC will also investigate methods to identify when RFI and/or EA is present, allowing the proposed EP techniques to only be employed under appropriated environmental conditions.