Convolution-backprojection image reconstruction for bistatic synthetic aperture radar

The algorithm presented accounts for the elliptical nature of the wavefronts over the ground patch (resulting in elliptical-arc projections) and is based on the convolution-backprojection (CBP) algorithm of computer tomography. Essentially, three changes were made to the CBP algorithm. First, instead of backprojection along straight lines, the backprojection is along the same elliptical arcs from which the data were taken. Second, each pixel in the image, during each backprojection, receives a weighting depending on its position in the image. Third, each projection receives an additional overall weighting depending on the positions of the transmitter and the receiver for the corresponding projection. As with CBP, each projection is convolved with a specified function before backprojection, and all of the backprojections are accumulated to form the final reconstructed image.