【摘要】 从对城镇用地的遥感信息机理分析入手,分析了城镇用地在LANDSAT TM 2、TM 3、TM 4、TM 5等各个波段上与其它地类的可分性。发现利用归一化植被指数NDV I和归一化水体指数NDW I,设定合适的阈值,能够有效地提取植被信息和水体信息,得到二值化图像。由谱间结构特征可知,城镇用地和裸地的TM 3-TM 2>0,城镇用地的TM 4-TM 3<0,而裸地的TM 4-TM 3>0,利用此特性可以区分城镇用地和裸地。对上述二值图像进行二值逻辑运算,得到城镇用地专题信息。研究结果表明,该方法的提取效率和精度都较高,与监督分类法和屏幕数字化方法相比,是一种行之有效的方法。更多还原

【Abstract】 Land covers in urban areas tend to change drastically over a short period of time due to rapid urbanization.Therefore,it is very important to quickly obtain the distributions and area of urban land-use.Remote sensing images are ideally used to monitor current land cover changes thanks to their rapid up-date capability.In this paper,the method of extracting urban land-use from Landsat TM data is discussed.Firstly,the mechanism of remote sensing for urban land-use is analyzed.Secondly,the differences of urban land-use and other land-use type are discussed.Third,the structure feature among spectrum of urban land-use and the other land-use types is analyzed.Vegetation and water can be extracted by NDVI and NDWI with suitable threshold.Urban land-use and bareness areas can be distinguished by the formula such as TM3-TM2>0 and TM4-TM3>0.This method is much faster and better accurate.The experiment results show that this method is very simple and effective to the semi-automatic extraction of the urban land-use.更多还原