Research On Enhanced Vegetation Index Algorithm And Its Application In The Ecological Environmenal Remote Sensing Production Subsystem

Along with the rapid development of high-resolution satellite technology, the various types of remote sensing image have been widely used in many industries. Remote sensing image has large amount of data and diverse types of image files. These characteristics bring a series of challenges to various applications: how to improve the speed of system processing remote sensing image, how to get better compatibility of remote sensing image processing method, and how to ensure the quality of system processing remote sensing image, are problems that should to be solved immediately in dealing with remote sensing image data in the remote sensing industry.The main function of Enhanced Vegetation Index Algorithm is to reduce the influence of noise from the air and soil at the same time, it steadily responses the condition of the region measured. Enhanced Vegetation Index Algorithm needs to deal with HDF4 image and GeoTIFF image. Currently, the library to operate HDF4 files developed by HDF GROUP is available for Fortran and C language, however other programming languages lack the method of operating HDF4 files systematically. Although ArcGIS supports most of raster data, it does not support HDF data format stored in multiple data sets.In the production of EVI product, the speed of production in C# project is obviously slower than the speed in IDL project. For the problems of processing remote sensing image in the project, this thesis proposes a new mechanism. The mechanism provides new access interface of HDF4 files, which is easy to add new functions, and it improves the production speed of EVI by block processing remote sensing image. In the ecological environment of remote sensing products production subsystem environmental which is proposed by environment ministry, this mechanism has been applied, and it has been analyzed and verified. The main achievements are the two points followed:(1)This thesis designs an access mechanism for operating HDF4 file of remote sensing images. This mechanism can not only create HDF4 data files stored in multiple data sets, but also add attributes to HDF4 file, and so on. This mechanism can not only apply in Enhanced Vegetation Index Algorithm, but also be packaged into a library file, to be called for related remote sensing system in multilingual environments.(2)It effectively improves the speed of the enhanced vegetation index products by remote sensing image block processing. According to the principle of matrix block operation does not affect the operating results, the mechanism of multi-thread and thread-pool is adopted respectively, and this mechanism takes the remote sensing image in chunks, which can significantly improve the processing speed of image and complete the production of enhanced vegetation index product faster.