Evaluation of JERS-1/SAR data for vegetation types in arid regions

摘要

Abstract: The purpose of this paper is to evaluate JERS-1/SAR data for determining vegetation types in arid regions. First, a noise speckle filter was applied to the original JERS-1/SAR image data using a Map Filter with an adaptive 7*7 window. Second, a small part of the study area was extracted for the full scene image for further analysis. The NRCS values of each extracted image data were computed with the known Calibration Factor for the NASDA supplied JERS-1/SAR data. Each image was assigned to one of the three categories with two selected threshold levels. These two threshold levels can be obtained by Otsu's Automatic threshold selection method.In order to generate color composite images, multi- temporal SAR images were registered with the JERS-1/OPS image using a second-order polynomial function. The accuracy of registration was within 0.5 pixel RMS error. Following this color composite an image based on above three scenes was generated to identify the training samples. Finally, the color composite image was evaluated for vegetation type discrimination in the study area. A test site along the Tarim River in the Tarim Basin, China, was selected for this purpose. !8