Improved Analytic Equations for Estimating the Performance of Truncated and Aberrated Gaussian-Beam Coherent Lidar

摘要

An approximate analytic equation for modeling the antenna efficiency of coherent lidar systems has been used by the lidar community for many years. This equation assumes perfect untrucated Gaussian beams and as such can lead to significant errors in performance predictions of real lidar systems. The best performance predictions are of course obtained by performing detailed numerical calculations that include all the intensity and wavefront details of the transmitted and back-propagated local oscillator beams, as well as the refractive turbulence profile in the atmosphere, but these calculations can be difficult and time consuming for trading the performance as system parameters are varied. We have developed an improved analytic approximation for calculating the antenna efficiency of Gaussian beam coherent lidar systems that includes the impact of beam quality, truncation, focus, and refractive turbulence. The development of this new equation and comparison of its predictions with those of numerical calculations and the historically used approximate analytic expression will be presented.