SOME BASIC ASPECTS OF RADAR TARGET IMAGING,

The classical basis of resolution as applied to radar target imaging was investigated with reference to point source targets in one dimension and their associated images. The imaging process can be represented by a Fourier integral operation on modified planar aperture data two methods of evaluating this integral by a digital computer are linear interpolation and Filons method. Curves were prepared which illustrate the aperture-resolution relationship and the sampling element placement within the aperture. Image distortion due to finite aperture size and to approximations of the far-field phase were examined by generating point source images on a computer and found to be distorted both in peak position and amplitude for finite apertures. Although phase correction for the distance between the constant-range surface and the planar aperture was shown by example to be essential for imaging, useful images can be obtained by such crude approximations as making plus or minus phase assignments to alternate lobes of the far-field pattern. Author