The historic development of spaceborne SAR antenna in Canada

摘要

The use of synthetic aperture radar on aircraft became well established in the first half of the seventies. It has enabled much better resolution to be obtained than that achievable with conventional radar. A conventional side looking imaging radar achieves range resolution by employing short RF pulses and azimuth resolution by means of a narrow antenna beamwidth. To create a narrow beamwidth with a physical aperture requires an antenna many wavelengths long. Due to the difficulty of building large airborne antennas, conventional side looking radars were generally restricted to low altitude aircraft and were operated at high microwave frequencies (10–30GHz).