LANDSAT-8卫星影像长条带数据处理

Study on processing method of LANDSAT-8 long strip satellite imagery

目的 LANDSAT-8卫星发射以来,美国地质调查局(USGS)向全球发布WRS(world reference system)分幅体系下的标准景产品,该产品覆盖区域较小。针对面向区域遥感应用需要较大覆盖范围长条带卫星影像的问题,提出一种长条带数据处理方法。方法长条带处理分为预处理、辐射校正和几何校正3个部分,包含了预处理、长条带数据辐射一致性纠正和姿轨数据精化等过程,解决了长条带影像处理的关键技术。结果利用3组LANDSAT-8数据进行实验,本文方法处理得到的长条带影像,辐射均一性得到提高,整体精度同单幅标准景产品的精度相当,且效率较传统的分景处理再镶嵌的方式提高了45.9%。结论本文LANDSAT-8长条带处理方法能够得到高质量的长条带影像,且处理效率较高,能够有效满足大区域遥感应用的数据需求。

Objective Since the launching of the LANDSAT-8 satellite, the U. S. Geological Survey has released LAND- SAT-8 standard scene products around the globe based on worldwide reference system. However, the coverage areas of a standard scene product are too small to satisfy regional remote sensing application, which needs long strip satellite products. The conventional method to obtain long strip satellite product is process-and-mosaic, which brings several problems, such as seam line problem and low processing efficiency. A novel LANDSAT-8 long strip satellite data processing method is proposed to solve the shortages of the conventional method. Method The proposed method was divided into three steps. First, in the preprocessing stage, auxiliary data were checked, and the imagery and the auxiliary data of LANDSAT-8 long strip satellite data were matched according to the uniqueness of data acquisition time. Second, in the radiometric correction stage, temperature sensitivity correction factor was introduced to eliminate the disproportion in brightness in LANDSAT-8 long strip satellite imagery, and a smoothing algorithm was proposed to avoid the seam line problem inside LANDSAT-8 long strip satellite imagery. Third, in the geometric correction stage, achieving high-precision georeferencing from LANDSAT-8 long strip products was needed for provision of good quality exterior orientation elements. Several algorithms were adopted to refine exterior orientation elements （ mainly include orbit data and attitude data）. Data verification algorithm were employedto identify and eliminate failure exterior orientation elements. Smooth filtering and Lagrange interpolation algorithm were used to keep continuity of orbits data. Orbital motion affections in gory data were removed, and Kalman filtering algorithm was introduced to obtain high accuracy of attitude data by combining it with the original attitude data. Result Experiments are designed and conducted on three sets of LANSDSAT-8 long strip satellite data, which were obtained in different time intervals and had different sizes. The conventional process-and-mosaic method were applied for comparison. Experimental results showed that the long strip satellite products produced by the proposed method obtain geometric accuracy same as those of the products produced by conventional method. Moreover, the long strip satellite products produced by the proposed method have no seam line problems. In addition, the efficiency comparison of two methods showed that the processing efficiency of proposed method increased by 45.9% on average. Conclusion The proposed method achieves high-quality long strip satellite imagery with a high efficiency than the conventional method, thereby greatly satisfying the needs of regional remote sensing applications.