A connection between monopulse azimuth and elevation error spectra for ship targets

During investigations of fading and glint for ship targets, experimental power spectra were calculated for fading and for azimuth and elevation glint errors. The radar used was a fixed frequency amplitude monopulse radar with error angles computed from the error ratios Re(Diff/Sum) for each pulse (`fast AGC´). Various spectral shapes and bandwidths were observed, but there was always a strong similarity of shape between azimuth and elevation glint spectra, which often seemed to differ only by a fixed number of dBs over a large frequency interval. Since, for a ship, the movements in azimuth and elevation generally are very different, this may be thought surprising. The experimental material is presented and an intuitive explanation is given, based on simulations and some deliberately simple computations. This indicates that the similarity of spectra is a normal phenomenon in a fast-AGC radar