  The Back-Projection Algorithm (BPA) is a time domain matched filtering
technique to form synthetic aperture radar (SAR) images. To produce high
quality BPA images, precise navigation data for the radar platform must be
known. Any error in position, velocity, or attitude results in improperly
formed images corrupted by shifting, blurring, and distortion. This paper
develops analytical expressions that characterize the relationship between
navigation errors and image formation errors. These analytical expressions are
verified via simulated image formation and real data image formation.
