STATISTICAL ANALYSIS OF A IF A CLASS OF IF CORRELATOR FM RANGING SYSTEMS

摘要

A statistical analysis technique for obtaining range responses of IF-correlator FM ranging systems is described under the assumptions of slowly varying, high-index frequency modulation and small propagation delays. It is shown that the range response for a system is determined by the functional relationship between modulation and reference and the envelope of the transmitted power spectrum, which (under the high-index FM assumption) is proportional to the first-order probability density of the modulation. Since statistical techniques are used, time/frequency domain analysis of the IF signal is not required and FM/FM systems or systems which use random modulations are conveniently analyzed. The range response is derived in terms of a sum of weighted quasi-autocorrelation functions which have been translated along the delay axis. The displacements and weightings depend on the harmonic series which describes the IF reference as a function of the frequency modulation.