Key points are not available for this paper at this time.
An account is given of the development of the AN/UPD-1 (XPM-1) system. This airborne mapping radar, by synthesizing an extremely long antenna which expands in length in direct proportion to radar range, provides a linear resolution in the azimuth direction that is constant for all radar ranges.
Cutrona et al. (Sat,) studied this question.