可见近红外、短波红外超光谱成像仪在轨数据处理技术研究

Onboard Processing of VNIR/SWIR Hyperspectral Imaging Spectrometer

分析了天基可见近红外、短波红外超光谱成像仪的数据特征,提出了一种用于可见近红外、短波红外超光谱成像仪的在轨数据处理系统。重点介绍了星上定标及非均匀性校正、星上数据压缩等算法。超光谱成像仪在地面定标的基础上进行星上辐射和光谱定标,用基于定标和基于场景两种方法对图像数据做非均匀性校正。星上数据去噪及压缩采用基于小波变换的方法,去噪后的数据用3D-Tarp算法压缩。该系统设计既考虑了算法的有效性,又考虑了恶劣的星上环境对时间、功耗等指标的限制,在尽量少损失信息的情况下,能有效去除噪声,提高信噪比,减少星上存储和下传的数据,提高图像质量。

This paper analyzes the characteristics of the data of the spaceborne VNIR/SWIR hyperspectral imaging spectrometer and presents a cost-effective approach for processing the hyperspectral image data on satellite. Algorithms for onboard calibration, nonuniformity correction and onboard data compression are introduced in detail. The imaging spectrometer performs onboard radiometric and spectral calibration based on the parameters gained in the laboratory on the ground. Nonuniformity correction based on both calibration and scenes are suggested in order to improve the quality of the image and 3D-tarp algorithm is used to compress the data. The design is not only effective, but also low-cost. On the condition that losing less information, it can increase SNR of the image and reduce data volumes that need to be stored on satellite and to be transfered to the ground.