红外与毫米波学报2018，Vol.37Issue(1)：112-118,7.DOI:10.11972/j.issn.1001-9014.2018.01.020
光束发散角对星载激光测高仪森林回波的影响
Impact of beam divergence angle on forest echo from satellite laser altimeter
摘要
Abstract
Vegetation height is an important parameter for biomass assessment and ecosystem structure monitoring.However,vegetation height data over large areas are difficult to obtain.Vegetation heights can be retrieved by using large-footprint satellite altimeter system GLAS waveforms,but the current method can only be used in relatively flat forest regions because over sloping mountainous areas,the effects of ground and canopy are mixing on the waveforms and cannot be distinguished.By establishing analytical model of forest target echo,the separation requirement of vegetation echo and ground echo from aliasing waveforms is derived.It is pointed out that the factors of leading to echo aliasing in addition to target roughness and slope,and beam divergence angle is also a factor.The broadening effect and waveform decomposition related to the beam divergence angle,surface roughness and topography slope is analyzed.By using the waveform simulation and GLAS actual waveforms,it is verified to decrease beam divergence angles can reduce the sensitivity of forest echo to sloping mountainous terrains and be more conducive to the retrieval of canopy heights.For laser altimeter to carry on satellite in the orbit of 500 ～ 600 km,the beam divergence angles is 40 ～ 60 μrad better.The result provides a meaningful reference for designing of satellite laser altimeter system for the retrieval of canopy heights over high sloping terrains.关键词
星载激光测高仪/光束发散角/光斑直径/森林回波Key words
satellite laser altimeter/beam divergence angle/footprint diameter/forest echo分类
信息技术与安全科学引用本文复制引用
王虹,马跃,李松,张智宇,黄科,易洪..光束发散角对星载激光测高仪森林回波的影响[J].红外与毫米波学报,2018,37(1):112-118,7.基金项目
对地高分辨率观测系统国家科技重大专项(11-Y20A12-9001-17/18,42-Y20A11-9001-17/18) （11-Y20A12-9001-17/18,42-Y20A11-9001-17/18）
国家自然科学基金(41506210,11574240) （41506210,11574240）
中国博士后科学基金项目(2016M600612)和中央高校基本科研业务费专项资金(2015212020201)资助的课题 （2016M600612）
测绘地理信息公益性行业科研专项(201512010)Supported by the National Science and Technology Major Project,National Natural Science Foundation of China (41506210,11574240) China (11-Y20A12-9001-17/18,42-Y20A11-9001-17/18),China Postdoctoral Science Foundation (2016M500612),and the Fundamental Research Funds for the Central University of Ministry Education of China (2015212020201),Public Science and Technology Research Funds Projects of Survey (201512010) （201512010）
