航天成像光谱仪CHRIS在内陆水质监测中的应用

Applicaton of Spaceborne Imaging Spectrometry CHRIS in Monitoring of Inland Water Quality

欧空局2001年10月22日成功发射的PROBA卫星上搭载了紧密型高分辨率成像光谱仪（CHRIS）,它可以提供高光谱分辨率、高空间分辨率和多角度的遥感数据,它代表了新一代的地球观测数据源。CHRIS有5种工作模式,其中模式2是专门为水体研究而设计的,它在400～1050nm的可见光至近红外有18个波段,每个波段数据的空间分辨率是17 m。CHRIS数据的高光谱分辨率、高空间分辨率和多时相覆盖的特点为内陆水质监测提供了有利条件。为了验证CHRIS在内陆水质监测中的具体应用,在太湖梅梁湾开展了水面综合试验,在梅梁湾均匀分布的14个水面采样点分别测量了水面光谱和水质参数。利用这些数据,同时结合CHRIS数据的光谱特征,建立了叶绿素浓度反演半经验模型,应用于CHRIS图像反演了太湖梅梁湾的叶绿素浓度分布图,并取得了较好的结果。最后指出CHRIS数据不但在内陆水质监测中具有巨大潜力,而且CHRIS遥感器是今后内陆水质监测卫星遥感器的典范。

On-board Autonomy（PROBA） satellite,which was developed by the European Space Agency,was launched on October 22,2001.PROBA satellite carries the Compact High Resolution Imaging Spectrometer（CHRIS） with high spatial resolution,hyperspectral resolution and multi-angular image data.CHRIS has five operating modes,among which mode 2 is optimized for water quality research,and has 18 bands in the visible/near-infrared wavelength from 400～1050 nm at a spatial resolution of 17 meters.All the characteristics of CHRIS make CHRIS well suited for inland water quality monitoring.To validate this,a campaign was carried out at Taihu Lake in East China to measure optical parameters of the water and the concentrations of water constituents on October 10,2005.Then,using these data,chlorophyll retrieval algorithm is developed and optimized to the spectral characteristics of the CHRIS sensor.The results of retrieved chlorophyll concentrations from CHRIS images are encouraging.