Patent ID: 6919839

Claim:
A synthetic aperture radar (SAR) for a moveable platform comprising: at least one antenna movable with the platform and directed through the ionosphere; a radar transmitter cooperating with said at least one antenna to propagate transmit pulses through the ionosphere, and subjecting the transmit pulses to ionospheric distortion based upon propagation through the ionosphere along a transmit path; and a radar receiver cooperating with said at least one antenna to receive echo pulses through the ionosphere based upon the transmit pulses, and subjecting the echo pulses to ionospheric distortion based upon propagation through the ionosphere along a receive path, said radar receiver comprising an ionospheric distortion estimator for estimating an individual ionospheric distortion for each received echo pulse based upon a time delay variation versus frequency, and a compensation filter for reducing the ionospheric distortion for each received echo pulse based upon the estimated individual ionospheric distortion associated therewith for providing a compensated echo pulse.