Simulation of coherent Doppler wind lidar measurement from space based on CALIPSO lidar global aerosol observations

The performance of a space-based 2.1-μm coherent Doppler wind lidar (CDWL) measurement at a single laser shot in clear-air conditions is computer simulated, based on the coherent Doppler lidar theory developed in the recent decades, and using the global aerosol distribution derived from one year (March 2007-February 2008) of the CALIPSO lidar measurements. The accuracy of radial wind velocity good estimates and the fraction of good estimates, depending on backscattered signals from aerosols, generally decrease with altitude. A critical altitude is defined as the altitude below which the good estimate fraction of velocity estimates is larger than 90.0%. With a laser pulse energy of 250 mJ at an off-nadir pointing angle of 45°, a telescope of 1 m in diameter and a vertical range resolution of ∼800 m, this critical altitude can reach an altitude of 4.0-5.0 km between 20°S and 40°N where dust and biomass burning aerosols are ubiquitous. The critical altitude gradually decreases as approaching the two poles and drops to 0.5-1.5 km in the polar regions. When the laser pulse energy is reduced to 100 mJ, the critical altitude is generally decreased by ∼0.5 km and can still reach an altitude of 3.5-4.5 km in the dust and smoke aerosol enriched tropical and subtropical regions. A laser pulse energy of only a few millijoules can still achieve velocity measurements with an RMS error smaller than 1 m s−1 and a good estimate fraction better than 90% in the lowest kilometers of the troposphere.

► For the first time spaceborne 2.1-μm coherent wind lidar simulations using CALIPSO lidar data. ► Reasonably selected yet technically available system parameters. ► Single-shot measurement with RMS errors <1 m/s is achievable in the lower troposphere.