COMPARISON OF 2-MU-M AND 10-MU-M COHERENT DOPPLER LIDAR PERFORMANCE

The performance of 2- and 10-mu m coherent Doppler lidar is presented in terms of the statistical distribution of the maximum-likelihood vel ocity estimator from simulations for fixed range resolution and fixed velocity search space as a function of the number of coherent photoele ctrons per estimate. The wavelength dependence of the aerosol backscat ter coefficient, the detector quantum efficiency, and the atmospheric extinction produce a simple shift of the performance curves. Results a re presented for a typical boundary layer measurement and a space-base d measurement for two regimes: the pulse-dominated regime where the si gnal statistics are determined by the transmitted pulse, and the atmos pheric-dominated regime where the signal statistics are determined by the velocity fluctuations over the range gate. The optimal choice of w avelength depends on the problem under consideration.