基于地表辐射亮温标准化的城市热环境遥感研究——以上海市为例

Study of Urban Thermal Environment Using Remote Sensing Data Based on Radiation Normalization

基于消除多时相遥感影像图像差异的重要性,在地表实测数据的支持下,分析了多时相热红外遥感影像地表辐射亮温标准化的方法,采用了辐射一致化和初温一致化2个步骤对图像进行处理,并以上海市为例研究了城市热环境的时空演变规律.结果表明:该方法可以明显消除不同成像条件对热红外遥感数据的影响,为城市空间热环境变化研究提供了有力工具.同时,通过统计分析和剖面分析表明,上海城市的扩展对城市热场的年变化幅度有放大作用;上海城市热中心并不在市中心,而位于能耗大、热源强度高的工业区.城市能耗和下垫面性质差异是影响城市热场差异的主导因素;通过剖面分析城区热场的细部结构,反映出城中心区亮温差异有正在缩小的趋势.

Based on the importance of eliminating the difference of multi-temporal remote sensing （RS） images, a model for calibration of thermal temperature was developed according to the characters of multi-temporal thermal infrared remote sensing data. In this model, two steps, including radiation normalization and original surface temperature normalization were used to complete the RS image processing and the space-time evolution characters of urban thermal environment change process were also analyzed through a case study in Shanghai. The results show that the impact of different imaging conditions to thermal infrared RS images can be clearly eliminated by this method, so this approach provides a reliable tool for studying urban thermal environment change; the urban expansion has a magnifying effect to the inter-annual change extent of urban thermal field in Shanghai; the urban thermal center is not the midtown but the industrial park with enormous energy consumption and high heat intensity; the dissipation energy and underlaying surface characters difference is the primary factors on the difference of the urban thermal field; and the brightness temperature in urban center area is reducing.