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Methods for atmospheric correction of solar-wavelength hyperspectral imagery over land
Methods for atmospheric correction of solar-wavelength hyperspectral imagery over land
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机译：陆地太阳波长高光谱图像的大气校正方法
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摘要
This invention discloses several improved methods of correcting for atmospheric effects on a remote image of the Earth's surface taken from above, wherein the image comprises a number of simultaneously acquired images of the same scene, each including a large number of pixels, each at a different wavelength band, and including infrared through ultraviolet wavelengths. One method is for retrieving the aerosol/haze amount (i.e., visible range) from an assumed ratio of in-band reflectances, rather than from an assumed reflectance value. Another method is for identifying cloud-containing pixels. This is used to improve the calculation of the spatially averaged radiance L*e and reflectance ρe images in standard equations. Another method greatly reduces the number of mathematical operations required to generate the reflectance values. This method operates by averaging the water vapor and ρe values over small groups of neighboring pixels, so that the same A, B, S, L*a parameter values may also be assigned to all pixels within the group. Yet another new method accounts for shifts in the wavelength calibration within the image, such as would be caused by spectral “smile”. This method loops the calculation of A, B, S and L*a over a set of possible wavelength shifts with respect to the input channel centers, and assigns the appropriate set of parameters to each pixel based on a pixel-location-dependent formula for the wavelength shift.
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机译：本发明公开了几种校正从上方拍摄的地球表面的远程图像上的大气影响的改进方法，其中该图像包括多个同时采集的同一场景的图像，每个图像均包含大量像素，每个像素均位于不同的位置波段，包括红外到紫外波长。一种方法是从带内反射率的假定比率而不是从假定的反射率值检索气溶胶/雾度（即可见范围）。另一种方法是识别包含云的像素。这用于改进标准方程中空间平均辐射L * e 和反射率ρ e 图像的计算。另一种方法大大减少了产生反射率值所需的数学运算次数。该方法通过对一小组相邻像素上的水蒸气和ρ e 值求平均值，从而使相同的A，B，S，L * a 参数值也可以分配给组内的所有像素。又一新方法解决了图像内波长校准的偏移，例如由光谱“微笑”引起的偏移。此方法在相对于输入通道中心的一组可能的波长偏移上循环进行A，B，S和L * a 的计算，并基于a来为每个像素分配适当的参数集与像素位置有关的波长偏移公式。
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