Polarimetric X/L/C-band SAR

A triband polarimetric synthetic-aperture radar (SAR) developed for remote sensing applications and installed in a US Navy P-3 aircraft is described. In this SAR, pulses are transmitted at either X-, C-, or L-band. They may be transmitted at either horizontal (H) or vertical (V) polarization and received at either horizontal or vertical polarization. Transmit and receive polarization, as well as frequency band, may be switched pulse-to-pulse. Up to four different waveforms may be interleaved, e.g. X_HH L_HV X_VV C_VH or X_HH X_HV X_VH X_VV (full-polarimetric model). A digital synthesizer produces the FM-chirp pulse. The pulse is emitted from a triband antenna that is kept perpendicular to the aircraft ground track by a three-axis, servo-driven positioner which compensates for aircraft pitch, roll, and yaw. Received pulses are digitized, preprocessed, and recorded to high-density digital tape. Test flights and preliminary imagery obtained are briefly noted