摘要
利用2007—2008年21个月CALIOP测量的夜间气溶胶后向散射系数的全球三维平均分布数据取代传统仿真中的气溶胶模型数据,对晴空条件下的2.1μm相干多普勒测风激光雷达的测风性能进行了计算机仿真研究。仿真结果表明,采用合理的系统参数设计,在20°S至40°N之间4.5km海拔之下单激光脉冲的径向风速误差普遍小于1m/s。以1m/s作为可接受风速误差的标准,符合标准的最大可测量海拔高度向两极方向递减,在南极附近减至1~2km。若10个激光脉冲平均测量,在对流层下层风速误差可降至0.5m/s以内,且在35°N附近最大可测量海拔高度可达5.5km。
A spaceborne Doppler lidar can be used to obtain the 3-dimensional（3D）global wind data.The measurement accuracy of radial wind speed depends strongly on backscattered signals from aerosols.The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation（CALIPSO）mission,launched by NASA in April 2006,created continuous vertically resolved observations of aerosols on a near-global scale using its onboard lidar（CALIOP）.Instead of using traditional modeled aerosol backscatter profiles,the measurement performances of a spaceborne 2.1μm coherent Doppler wind lidar（CDWL）are simulated using mean zonal-vertical and longitudinal-vertical aerosol backscatter distributions retrieved from 21 months data（from Jan.2007 to Dec.2008 except Aug.to Oct.in 2008）of CALIOP night time measurements in clear-air conditions.The aerosol backscatters at 2.1μm are derived from the CALIOP measurements of aerosol backscatter coefficient at 532 nm by using Srivastava＇s relationship.A computer simulation tool for the measurement performance simulation of a CDWL system has been developed using MATLAB.With a laser pulse energy of 1Jand a telescope of 1min diameter and appropriate selected parameters,the simulated radial speed error is less than 1m/s for a singleshot measurement within 4.5km altitude between 20°S and 40°N.With 1m/s as a benchmark of the acceptable speed error,the highest measurable altitude decreases toward the two poles from the equator and decreases to an level between 1km-2km in the southern remote ocean.The error can be further reduced to a certain value less than 0.5m/s in the low troposphere when 10 laser shots are averaged and at the same time the measurable altitude reaches a maximum close to 5.5km around 35°N.
出处
《中国海洋大学学报（自然科学版）》
CAS
CSCD
北大核心
2017年第1期119-125,共7页
Periodical of Ocean University of China
基金
国家自然科学基金项目(41228008
41376180)资助~~
