Operationally, SAR has several striking advantages. First, with a small physical antenna operating at wavelengths suitable for long-range mapping, SAR can provide azimuth resolutions as fine as a foot or so. Second, by increasing the length of the array in proportion to the range of the area to be mapped, the resolution can be made independent of range. Third, since the array is formed in the signal processor, the basic SAR technique can conveniently be adapted to a wide variety of operational requirements.