摘要由于遥感技术的快速、准确性,水资源调查、土地分类、监测管理、工程地 质调查和自然灾害评估等方面的水体信息提取工作已经开始大规模运用遥感技 术。随着遥感技术的快速发展,利用遥感影像来进行水体的监测、调查和分析已 经成为一种必然趋势。目前,遥感影像的空间分辨率逐渐提高,高分辨率遥感凭 借其能够更清晰地表现地物结构、布局及纹理尺寸,表现出极为巨大的优势。高 分辨率遥感技术的运用,越来越广泛。69945
水体提取是利用水体在一些波段上和其他地物类型拥有明显不同的反射率, 从而把水体和其他地物区分开来的遥感技术。和其他地物类型相比,水体在整个 光谱范围内都表现出较弱的反射率。水体在不同波段的反射率由低到高大致可以 表示为:中红外波段<近红外波段<红光波段<绿光波段<蓝光波段。但同时植被、 土壤、建筑物等这些波段吸收能量较小,在这些波段具有较高的反射率。水体在 这些波段上与其他地物类型具有明显的区别,因此这一波段范围可以被用来区分 水体与植被、裸地和建筑物等其他地物。但当水中含有其他物质时,反射光谱曲 线会发生变化。
本文针对资源三号卫星的长江口的高分影像,分别采用分别采用归一化差分 水体指数阈值法(NDWI)、监督分类法和归一化植被指数法(NDVI)对影像进行 水体提取,根据提取结果分析和比较各种方法的优势与不足,并根据最终的比较 结果找出更适合长江口地形的水体提取方法。
毕业论文关键词:高分辨率 水体提取 归一化差分水体指数 归一化植被指数 监督分 类
Water extraction based on high-resolution satellite image
Abstract Due to the fast, accuracy of remote sensing technology, water resources investigation, land classification, monitoring and management, engineering geological survey and natural disaster evaluation of water information extraction work has begun large-scale use of remote sensing technology. With the rapid development of remote sensing technology, monitoring, investigation and analysis of water using remote sensing image has become an inevitable trend. At present, the spatial resolution of remote sensing image is gradually improved, and high resolution remote sensing can show the feature structure, layout and texture size more clearly. The application of high resolution remote sensing technology is more and more extensive.
Water body extraction is a kind of remote sensing technology, which uses the water body in some bands and other surface features to have different reflectivity. Compared with other types of ground objects, the water body has a weak reflectivity in the whole spectral range. The reflectivity of water body at different wavelengths can be expressed as follows: mid infrared band<near infrared band<red band<green band<blue band. But at the same time, vegetation, soil, buildings and so on these bands absorb the energy is small, has the high reflectivity in these bands. Water in these bands with other feature types have obvious difference, so the wavelength range can is used to distinguish between water and vegetation, bare land and buildings of the other features. But when the water contains other substances, the reflection spectrum curve will change.
This paper aims at the Yangtze River Estuary of the resources on the 3rd satellite high resolution image, respectively, using respectively using normalized difference water index threshold method (NDWI), supervision classification and normalized difference vegetation index (NDVI) water extraction of the image according to the extraction result analysis and comparison of the advantages and disadvantages of various methods, and according to the final comparison results to find more suitable for terrain of Yangtze River estuary water extraction method.