Siegman’s theorem is used to express the heterodyne signal from incoherent backscatter lidar in terms of fields in the target plane. It is then shown directly that, contrary to some previously documented predictions, the mean return from a matched transceiver lidar is, as a consequence of its self-adaptive properties, invariably degraded less by turbulence than is that of a bistatic system; established results for the irradiance statistics of beams propagating in the turbulent atmosphere enable beam centroid and scintillation wander tracking to be distinguished as contributing to this result. A combination of the two systems can give rise to near-field transceiver returns that are greater than returns for free-space propagation of untruncated Gaussian beams. Target-plane expressions for signal variance display the dependence of signal statistics on antenna geometry, and application of these results to returnpower estimation is briefly discussed.
© 1981 Optical Society of AmericaPDF Article