The ability of a radar system to resolve two or more separate returns
from a combined echo is related to the effective correlation band-widt
h of the pulse emitted by the ladar system. Phase modulation of an out
going pulse introduces additional frequency components, which increase
s the effective correlation bandwidth of the pulse and thus improves t
he range resolution of the system. In this paper, we discuss the gener
al theoretical basis for achieving improved range resolution using a m
odulated waveform and a matched filter receiver. We then demonstrate t
hese concepts by considering the particular case of improved range res
olution for a sinusoidally phase modulated carrier with a rectangular
amplitude function. We also perform computer simulations with a realis
tic pulsed ladar envelope possessing the same modulation function. Our
calculations indicate that the resolution of a pulsed ladar system ma
y be improved by a factor of 70 with a phase-modulated pulse and a mat
ched-filter receiver.