A method for detection of deformations in large phase array antennas for spaceborne synthetic aperture radars

A method to measure deformations in large, planar phased array antennas used in spaceborne synthetic aperture radars (SAR) is described. This method has the advantages that the deformation measurements can be performed anywhere in orbit and that no additional sensor is required. Indirect test results using the SEASAT SAR data indicate that this technique can detect deformations of small fractions of a wavelength.