基于浓密植被法的HJ-1B星CCD影像大气校正

Atmospheric Correction for HJ-1B CCD Image Using Dense Dark Vegetation Method

利用红波段(0.66μm)与中红外波段(1.66μm)表观反射率之间的线性关系估计出红波段的反射率,然后利用红波段估计的反射率与其表观反射率,结合6S辐射传输模型构建查找表,查表得0.55μm处的气溶胶光学厚度(Aerosol Optical Depth,AOD)值,从而实现各个波段大气校正.通过林地校正前的表观反射率、大气校正后反射率和MODIS地表反射率的对比以及裸土校正前的表观反射率、大气校正后反射率和光谱库中反射率的对比,结果表明该方法对HJ-1B星CCD数据进行大气校正可取得较好的效果.

It used the spectral correlation between red （0. 66μm） and short-wave infrared （1.66μm） channel to drive atmospheric properties. It utilized the apparent reflectance at 1.66μm channel to estimate the surface reflectance at 0. 66μm, and then used the estimated surface reflectance and apparent reflectance at 0.66μm to get the Aerosol Optical Depth （AOD） at 0.55 μm. Through many times 6S model operations, it established the lookup table and got the AOD at 0. 55μm; it achieved the atmospheric correction of different bands. Through the comparative analysis of spectral curve of dense mature forest before and after atmospheric correction and MODIS surface reflectance, and of bare soil before and after at- mospheric correction and surface reflectance in spectral libraries, the result indicated that us- ing the approach in the paper can obtained a better result in atmospheric correction for HJ-1B CCD imagery data.