The Accuracy of Radar Range Measurements Using Non-Optimum Filters

The accuracy with which radar range may be determined in a single measurement using non-optimum filters is treated in this paper. In the particular case of a rectangular transmitted-signal waveform, as used in conventional radars, certain difficulties arise in theoretical calculations, since under ideal conditions a zero-variance range (delay) estimate should be possible. Skolnik has overcome this difficulty by assuming a signal pulse with finite rise times, but has maintained the assumption of the availability of a matched filter. In the present paper the matched-filter assumption has been abandoned and a formula for the theoretical accuracy is derived for this sub-optimum case. The specific case of a rectangular pulse and a Gaussian filter is then considered and theoretical results are compared with measurements carried out for this case.