The basic idea of synthetic aperture radar (SAR); a side-looking case is illustrated. Two example scatterers, A and B, are shown in the ground scene. Le = maximum flight path length for effective SAR processing.
The range-dependent Doppler-time function of surface objects (reference objects A and B of Fig. 1), as the synthetic aperture radar passes by, for (a) A and B close to the flight path and (b) A and B at greater range.