多时相Landsat数据相对辐射归一化方法研究及应用-南京林业大学.doc

多时相Landsat数据相对辐射归一化方法研究及应用 魏辛源，李明诗，孙颖，杨婳婷* （南京林业大学森林资源与环境学院，江苏 南京 210037） 摘要：多时相Landsat数据的相对辐射归一化处理是进行变化检测、影像拼接等不可缺少的重要步骤。本文以南京市主城区1992年、1998年、2003年、2007年和2011年5景Landsat TM热红外波段数据为源数据，反算亮温图像并与8个地面气象站采集的实时温度数据建立回归模型，反演地表温度，然后采用伪不变特征相对辐射归一化方法和多元变化检测相对辐射归一化方法对5期地表温度数据做归一化处理，分级操作后评价南京市热岛效应的时空变化特征。最后引入均方根误差和变异系数2个统计特征参数，评价两种相对辐射归一化方法的优劣。结果表明：经过两种归一化方法调整后的数据都有利于对南京市热岛效应的分析；在后续的热岛效应分析中，多元变化检测相对辐射归一化法处理后的影像优于伪不变特征相对辐射归一化处理的影像；多元变化检测归一化法克服了人工选取样本点中存在的主观因素，但其计算相对较复杂。 关键词：Landsat；多时相；伪不变特征；多元变化检测；归一化 Assessing relative radiometric normalization performances and their applications from Multi-temporal Landsat thermal observations WEI Xinyuan, LI Mingshi* (College of Forest Resources and Environment, Nanjing Forestry University, Nanjing 210037，China) Abstract:Relative radiometric normalization of multi-temporal Landsat images is quite essential and necessary for change detection analysis and image mosaic operation. Taking Nanjing as the case study, using the Landsat TM observations dated in 1992, 1998, 2003, 2007 and 2011, the surface brightness temperatures of the primary urban areas of Nanjing were derived first, followed by the retrieval and mapping of the true ground temperatures through linear regression models constructed based on the nearly simultaneous temperature data collected from the 8 local observatories. Relative radiometric normalization based on the subjectively identified pseudo-invariant features (PIF) and the objective multivariate alteration detection (MAD) algorithms were applied to normalize the true surface temperature images to eliminate the seasonal and annual variations, which makes all the resulted ground temperature images comparable directly. Furthermore, the spatio-temporal patterns of the heat islands were mapped or characterized by implementing the grading operations. The results showed that the two suites of normalized images derived here were more beneficial and accurate to characterize urban heat island effects than the original images. In add