可见短波红外高光谱相机有效载荷观测能力及应用前景

Observation Capability and Application Prospect of the Advanced Hyperspectral Imager

高分五号卫星上的主载荷之一——可见短波红外高光谱相机(AHSI)是国际上首个采用改进型Offner结构凸面光栅分光的星载高光谱相机,以60km幅宽、30m空间分辨率和5~10nm光谱分辨率,同时获取地物在400~2 500nm范围内共330个连续谱段的空间信息和光谱信息,具有突出的地物探测和识别能力。通过地面测试与在轨测试验证了该相机的主要性能指标。与国际上经典的高光谱相机相比,该相机幅宽提高8倍,光谱数增加近百个,信噪比提升近4倍;与德国、日本、意大利等国家高光谱相机比较,AHSI在幅宽和光谱通道数等方面具有明显优势,其综合性能指标处于国际领先水平。该相机将为遥感应用如生态环境监测,国土资源和地质矿产调查,以及灾害监测,农、林、牧业精细作业,城市规划等中的许多关键问题提供解决方案。

The advanced hyperspectral imager(AHSI),one of the main payloads of the GF-5satellite,is the first spaceborne hyperspectral sensor that utilizes both the convex grating spectrophotometry and an improved three concentric-mirror(Offner)configuration.It is designed to be capable of resolving 330spectral bands from 400to 2 500nm with 30mground resolution,5-10nm spectral resolution and 60km swath width.It has outstanding capacity of object detection and identification.The main performance metrics are obtained and further validated via well-designed experiments both on the earth and on the orbit.Compared to the existing instruments overseas,the imaging width is superior(8times),the number of spectral bands has increased by hundreds,and the signal to noise ratio(SNR)has improved by 4times.Compared to the instruments planned by Germany,Italy,and Japan,etc.,AHSI has competitive performance and has obvious advantages in terms of the swath width and the number of spectral channels.AHSI will be able to address many key science questions of remote sensing applications,such as,ecological and environmental monitoring;investigation of geology and mineral resources,land&resources;disaster monitoring;agriculture,forestry,animal husbandry fine work,and city planning.