Airborne bistatic SAR imaging for parallel translational variant configuration

The transmitter and receiver at the difference velocity along parallel trajectories constitutes the parallel translational variant configuration whose echoes have two-dimensional space variant properties. The paper proposes a full analytic imaging algorithm for this configuration in two-dimensional frequency domain. Considering the contribution difference in the Doppler modulation ratio between the transmitter and receiver, their Doppler contribution ratio is used as the weighting factors to derive two-dimensional frequency spectrum of the echo of a target. Utilizing the relations of a target relative to the transmitter and receiver tracks, the spectrum is expressed a uniform formula relative to the receiver track. After compensating the bistatic deformation term, the 2D-CZT is used to correct the residual migration in range and azimuth, thus the focused image is obtained. The simulations validated the 2D-CZT algorithm.