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遥测地表温度与比辐射率的迭代反演方法──理论推导与数值模拟 总被引：16，自引：0，他引：16
首先在地表比辐射率为已知的条件下,提出一个非线性迭代温度反演模型,我们对不同的地表和大气条件进行了模拟计算,结果表明当大气温度廓线误差－２Ｋ－２Ｋ,水汽廓线误差±２０％时的温度均方根误差为０．４８Ｋ。当大气模式误差一个模式时反演的温度均方根误差为０．８５Ｋ。在此基础上,引人相邻像元的概念,相邻像元的大气状况可以认为是相同的,应用两个时相的遥感影像数据,假定在两个相近时相之间地表比辐射率值不变,建立地表比辐射率与温度的反演模型。我们对不同的地表和大气条件进行了模拟计算,结果表明当大气温度廓线误差－２Ｋ－２Ｋ,水汽廓线误差±２０％时地表温度均方根误差小于１．５Ｋ,地表比辐射率均方根误差小于０．０２,地表辐射均方根误差为１％;当大气温度廓线误差－２Ｋ－２Ｋ,水汽廓线误差±１０％时,地表温度均方根误差小于１．０Ｋ,地表辐射均方根误差小于０．６％。 相似文献
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卫星微波被动遥感云中液态水的研究进展 总被引：3，自引：1，他引：2
卫星微波被动遥感云中液态水的研究在近30年中取得了较大的进展.卫星遥感仪器的不断进步、探测精度的不断提高为卫星微波被动遥感云中液态水提供了技术和资料保障,在此基础上针对卫星微波被动遥感云中液态水技术而发展的一些统计反演方法和物理反演方法不断地得到改进、完善和提高.文中主要就各个时期发展的主要反演方法做了简要回顾,概括了这些反演方法的关键技术,评述了各自的优点和局限性.由于海表和陆表的辐射特性的巨大差异,分别就海洋上空和陆地上空云中液态水的统计和物理反演技术方法进行了综述,并进行了比较.针对地表比辐射率这一制约陆地上空云中液态水反演技术发展的瓶颈问题,也进行了相关评述和讨论. 相似文献
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本文研究发展利用GMS 5/VISSR每小时卫星观测资料反演地表温度的方法,首先利用时空判断法进行云检测寻找晴空像元,然后从辐射传输方程出发,由实时探空资料求取大气上行、下行辐射率及大气透过率,根据由AVHRR NDVI导出的地表比辐射率,用单时相双光谱分裂窗法反演得到地表温度.比较反演结果与54511站及其他中国基准站2000年地面0cm地表温度实测值,相对于国际上其他经验公式而言,本文算法在精度上有所提高.敏感性分析试验着重于大气衰减的影响.基于本文算法,给出了内蒙中东部地区地表温度连续4天的变化实例以及东亚部分陆地“纯晴天”地表温度图. 相似文献
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Recent advances in thermal infrared remote sensing include the increased availability of airborne hyperspectral imagers (such as the Hyperspectral Thermal Emission Spectrometer, HyTES, or the Telops HyperCam and the Specim aisaOWL), and it is planned that an increased number spectral bands in the long-wave infrared (LWIR) region will soon be measured from space at reasonably high spatial resolution (by imagers such as HyspIRI). Detailed LWIR emissivity spectra are required to best interpret the observations from such systems. This includes the highly heterogeneous urban environment, whose construction materials are not yet particularly well represented in spectral libraries. Here, we present a new online spectral library of urban construction materials including LWIR emissivity spectra of 74 samples of impervious surfaces derived using measurements made by a portable Fourier Transform InfraRed (FTIR) spectrometer. FTIR emissivity measurements need to be carefully made, else they are prone to a series of errors relating to instrumental setup and radiometric calibration, which here relies on external blackbody sources. The performance of the laboratory-based emissivity measurement approach applied here, that in future can also be deployed in the field (e.g. to examine urban materials in situ), is evaluated herein. Our spectral library also contains matching short-wave (VIS–SWIR) reflectance spectra observed for each urban sample. This allows us to examine which characteristic (LWIR and) spectral signatures may in future best allow for the identification and discrimination of the various urban construction materials, that often overlap with respect to their chemical/mineralogical constituents. Hyperspectral or even strongly multi-spectral LWIR information appears especially useful, given that many urban materials are composed of minerals exhibiting notable reststrahlen/absorption effects in this spectral region. The final spectra and interpretations are included in the London Urban Micromet data Archive (LUMA; http://LondonClimate.info/LUMA/SLUM.html). 相似文献
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P. K. Pasricha B. S. Gera S. Shastri H. K. Maini T. John A. B. Ghosh M. K. Tiwari S. C. Garg 《Boundary-Layer Meteorology》2003,107(2):469-482
Nocturnal measurements of air temperature, relative humidity, temperatureinversion-layer thickness, water vapour path and visibility-through-fog, madeunder non-foggy and foggy conditions in winter over two seasons at Delhi,are analysed to study the decrease in both rate of cooling and temperature inversion-layer thickness during the course of nights followed by fog occurrence.In particular, the decrease in the rate of cooling, compared to that on non-foggynights, is explained as due to the greenhouse warming effect by a layer of excessive,near-saturated water vapour trapped in a temperature inversion. Next, the linearprogramming technique is employed to forecast the occurrence of fog, where thevisibility-through-fog is minimized through its linear regression equation with thepair of variables, mean air temperature and temperature decrease over one hour(measuring rate of cooling at two convenient hours) in the pre-midnight period.This technique provides feasible solutions that enables one to forecast the occurrenceof radiative fog. 相似文献
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热红外遥感岩矿信息提取研究进展 总被引：12，自引：0，他引：12
热红外遥感是岩矿遥感信息领域起步未久,且表现出巨大潜力的技术手段。从岩矿发射率光谱、数据处理及信息提取技术方法、应用研究3个方面对热红外遥感在岩矿信息提取中的研究现状进行了全面总结,在此基础上对其发展难点及趋势进行了讨论,并对其在地质领域的应用前景进行了评估。在数据获取方面,高光谱分辨率数据是应用要求与发展趋势;数据处理方面,对大气影响进行定量评价并力求高精度的大气校正方法是难点与不可回避的问题,大气是影响数据质量的最大因素。岩矿热红外遥感信息机理（矿物发射率光谱特征与机理、光谱混合行为、光谱变异因素）的定性研究取得了一定进展,定量化的研究是发展趋势;在地质领域,因为可以对矿物种类(包括不含水矿物)及含量进行高精度提取的突出优势,不仅在矿产勘探,而且在基础地质研究方面将发挥巨大作用。 相似文献
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自然表面比辐射率测定方法的理论分析和实验 总被引：5，自引：0，他引：5
本文对野外现场测定自然表面比辐射率的方法进行了理论分析和观测实验.结果表明文献[1]的测量方法在估计比辐射率时偏高而使表面温度估计偏低,对原方法改进后可得到很好的改善;实验结果与理论计算值有很好的一致性,以部分计算值代替实测值,可减少实测项目,使观测方案进一步简化且仍保持良好的精度.应用改进后的方法,我们在“黑河试验”现场测定了几种不同下垫面的比辐射率. 相似文献
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In order to achieve the in-orbit absolute radiometric calibration of the operational meteorological satellites’ thermal infrared channels, China Radiometric Calibration Sites (CRCS) were established and the accuracy of the CRCS in-orbit field absolute radiometric calibration methods (FCM) for thermal infrared channels (TIR) was evaluated and analyzed based on TERRA/AQUA MODIS observations. Comparisons between the MODIS at pupil brightness temperatures (BTs) and the simulated BTs at the top of atmosphere using radiative transfer model (RTM) based on field measurements showed that the accuracy of the current in-orbit field absolute radiometric calibration methods was better than 1.0K (@ 300K) in thermal infrared channels. Therefore, the current CRCS field calibration method for TIR channels applied to Chinese meteorological satellites was with favorable calibration accuracy: for 10.5~11.5 μm channel was better than 0.747 K and for 11.5~12.5 μm channel was better than 0.851 K. 相似文献
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