北京一号小卫星多光谱图像波段配准和图像变形评价

The Geometric Evaluation of Beijing-1 Microsatellite Multispectral Images

北京一号小卫星是中国和英国联合研制的一颗实用型、对地观测微小卫星,星上携带中分辨率32m多光谱(近红外、红和绿波段)和4m全色两种有效载荷。为了提高多光谱图像的宽度和时间分辨率,北京一号小卫星的每个多光谱波段都是由两个相机独立成像然后拼接而成。由于这种成像方式很难保证6个相机的主光轴平行,导致图像配准精度较低。针对北京一号小卫星的这种成像特点,本文在图像灰度交叉相关匹配的基础上,发展了一种高精度波段配准算法来评价北京一号小卫星的波段配准精度,并在波段配准的基础上,评价北京一号小卫星多光谱图像的变形一致性。

Beijing-1 microsatellite is an applied earth observing microsatellite of China. It combines SSTL＇ s standard Disaster Monitoring Constellation （DMC） muhispectral camera with a high resolution panchromatic imager. To enlarge its swath and shorten the revisiting time, every muhispectral band is combined by two part images which were captured by two separate cameras. This design must add the error of the band registration. To assess Beijing-1 microsatellite, this paper introduces an effective method to evaluate the band registration accuracy. The method is based on cross-correlation of image digital number. Based on the result of band registration, this paper presents a new method to assess the images＇ distortion and its coherence of three bands.