A review of sparse frequency linearly frequency modulated (SF-LFM) laser radar signal modeling with preliminary experimental results

摘要

Sparse frequency linearly frequency modulated (SF-LFM) laser radar (ladar) signals have been shown through analytical and numerical modeling to increase the effective bandwidth of a ladar signal without the need for large bandwidth modulation sources. SF-LFM waveforms increase the effective bandwidth, and hence the range resolution, of ladar signals by superimposing multiple frequency offset laser lines into the same waveguide and then coupling the superimposed lines into a single linear frequency modulator (or a quadratic phase modulator). While SF-LFM ladar signals have the distinct advantage of producing lager bandwidth signals without sacrificing linearity, the segmented bandwidth nature of the SF-LFM ladar signals can introduce additional ghosting in the matched filter output. This manuscript will review the previously developed models for SF-LFM ladar signals, and discus some preliminary experimental data which verifies some of the results of the previous models.