高分一号与Landsat-8影像在荒漠绿洲过渡带应用对比

Application Comparison Between Landsat-8 OLI and GF-1 in Desert-oasis Ecotone

针对国产高分一号卫星(GF-1)成像质量是否可以满足区域生态环境监测需求的问题,开展了宽幅多光谱相机(wide field view,WFV)在荒漠绿洲过渡带的成像质量评估研究。从辐射质量、纹理、地类识别精度和归一化植被指数等方面构建评估指标,定量分析了GF-1 WFV和Landsat-8OLI在荒漠绿洲过渡带的成像质量差异。结果表明:GF-1 WFV影像虽然具有较高的空间分辨率,但在辐射质量、地类识别效果、纹理信息及植被指数等方面与Landsat-8OLI相比有一定差距;GF-1 WFV影像的信噪比优势明显,对噪声的抑制效果较好;通过与纹理信息的波段组合,可以有效提高GF-1WFV影像的地物识别效果,缩小与Landsat-8OLI在分类精度上的差距;鉴于明显的光谱范围差异,二者归一化植被指数数据在协同应用的过程中宜分地物类型转换,在西北荒漠绿洲过渡带的国土资源调查、城市规划、农情监测等方面可发挥积极作用。

Despite the growing rapid application requirement in arid and semi-arid areas of northwest China, whether the image quality of GF-1 satellite can satisfy the requirement of eco-environment monitoring is still uncertain. Thus, the assessment process about image quality of GF-1 satellite Wide Field View data （GF-1 WFV） were carried out in this paper. Compared with Landsat-80LI satellite data,the radiation quality,texture feature,classification accuracy of land type and normalized difference vegetation index （NDVI） were built to analyze the imaging difference of GF-1 WFV in desert-oasis ecotone. The results show that GF-1 WFV image is inferior to Landsat-80LI image by radiation quality, classification accuracy of land cover, texture feature and vegetation index,despite higher spatial resolution. GF-1 WFV image has a great advantage in the aspect of signal noise ratio （SNR） and noise suppression. With a good classification accuracy of GF-1 WFV, the accuracy still can be enhanced and the difference with Landsat-80LI narrow by the combination of texture feature and spectral. For the obvious difference of spectral and underestimation of NDVI of GF-1 WFV, the linear transformation based on land cover between GF-1 WFV and Landsat-80LI should be conducted in the process of collaborative application.