基于Sentinel-1A雷达影像的崇明东滩芦苇盐沼植被识别提取

In this study we analyzed the temporal variation of the back-scattering intensity of the phragmites australis to extract its spatial distribution and explore the prospect of applying the Sentinel-1A SAR data for salt marsh monitoring in the Yangtze River estuary. Using the 11 Sentinel-1A VV+VH dual-pol SAR images from 2016, the temporal variation of the main land features in the southern part of the Chongming tidal flat was characterized. The findings showed that the variation of back-scattering intensity in the VV band was more remarkable than the VH band, and the dB value of the phragmites australis was much stronger than the other features during the leaf-off period. Based on the analysis, the phragmites australis was distinguished from other land types in the study area in a relatively high accuracy of 88.7%. During the study, we took into consideration of the images acquired during the leaf-off period to extract the phragmites australis, and utilized the images under different tidal levels to obtain the better result. Based on the correlation analysis, a favorable positive correlation existed between the back-scattering intensity and the temporal-adjacent optical normalized difference vegetation index (I_NDV) with a correlation coefficient of 0.78.