非星历表法去除MODIS图像边缘重叠影响的研究

Eliminating Bowtie Effect of MODIS Data Without Ephemeris

由于地球曲率的影响以及MODIS(MODerate-resolutionImagingSpectroradiometer)探测器的特点,使得MODISL1B产品中存在着图像边缘重叠影响(BowtieEffect),俗称"双眼皮"现象,即在图像的边缘部分存在有部分重叠。BowtieEffect影响了边缘数据的使用,并且几何校正之后仍无法去除,因此该现象必须在几何校正之前加以去除。使用星历表数据去除BowtieEffect计算较为复杂,同时用户必须获得当天的星历表。比较了去除BowtieEffect的两种简单方法,,并对图像了进行几何校正,结果表明方法二更为适用。

There exist bowtie effects in MODIS L1B data because of the Earth's curvature and the characteristics of MODIS detector, namely some datum is overlapped at the edge of a scan. Bowtie effects can't be eliminated after geometry calibration, so eliminating bowtie effects has to be done before geometry calibration. It can be eliminated using ephemeris which is complex and difficult for common user to get ephemeris. We used two simple methods and compared their location accuracy after geometry calibration in this paper.