一种拓展的半物理时空融合算法及其初步应用

Landsat 5卫星较低的时间分辨率(16天)使得其很难获得大区域的、时相一致的清晰影像数据集。本文发展了一种基于半物理模型的时空融合算法-即乘性调制融合算法,并借助多时序的MODIS反射率数据来生成多时相的Landsat TM/ETM+反射率合成影像,经镶嵌后得到区域尺度的高时空分辨率地表反射率数据集(Landsat TM/ETM+)。本文利用吉林省2006年—2011年的Landsat 5 TM地表反射率数据以及500 m的MOD09A1反射率产品来生成3个时相的Landsat 5 TM反射率合成数据,从而获得研究区在上述时相下地表反射率数据的镶嵌图。初步分析表明,所生成的Landsat 5 TM反射率数据的光谱分布特征与MOD09A1反射率数据较为一致,且图像在整体上光谱特征的连续性较好。

Spatial-temporal fusion algorithm based on an extended semi-physical model and its preliminary application

Regional and clear data sets on a specified date is difficult for Landsat 5 because of low temporal resolution (16 d). In this study, we develop a spatial-temporal fusion algorithm based on semi-physical model-multiplicative modulation fusion algorithm and generate synthetic multi-temporal Landsat 5 TM/ETM+ reflectance data with the help of multi-temporal MODIS reflectance data. A regional scaled data set of surface reflectance with high spatial and temporal resolution is retrieved after image mosaicking. In this study, we generate three temporal Landsat 5 TM reflectance data that cover Jilin Province in China by utilizing Landsat 5 TM surface reflectance data, and the 500 m MOD09A1 reflectance products were collected from 2006 to 2011.Surface reflectance mosaic data that cover the study area were then derived. Primary analysis shows that the generated Landsat 5 TM reflectance data have good agreement with the MOD09A1 reflectance data in spectral distribution features, and color distribution appears to be uniform (no obvious color differences).