An Atmospheric Radiosounding Database for Generating Land Surface Temperature Algorithms
An Atmospheric Radiosounding Database for Generating Land Surface Temperature Algorithms
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DOI：
10.1109/tgrs.2008.916084
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发表时间：
2008-04
影响因子：
8.2
通讯作者：
J. M. Galve;C. Coll;V. Caselles;E. Valor
中科院分区：
文献类型：
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作者：
J. M. Galve;C. Coll;V. Caselles;E. Valor
编制了一个全球、无云和大气无线电探空剖面数据库，目的是模拟星载传感器的热红外辐射测量。利用Terra/中分辨率成像光谱仪（MODIS）和Envisat/高级沿着迹扫描辐射计（AATSR）数据，对地表温度（LST）进行了分裂窗（SW）和双角度（DA）反演。该数据库包含382个在陆地上获得的无线电探空剖面，可降水量分布几乎均匀，在0.02和5.5厘米之间。使用MODTRAN 4代码对0度到60度之间的六个视角进行辐射传输计算。由此产生的辐射光谱进行卷积的响应滤波器功能的MODIS波段31和32和AATSR通道在11和12妈妈。利用模拟数据库，开发了适用于MODIS和AATSR数据的SW算法和适用于AATSR数据的DA算法。这两种类型的算法是二次的亮度温度差，并明确地依赖于地表发射率。SW和DA算法进行了验证与实际地面测量LST同时收集到的MODIS和AATSR观测在一个网站位于靠近城市的瓦伦西亚，西班牙，在一个大的，平坦的，热均匀的水稻作物的面积。对于两种传感器，在最低点时SW算法获得的结果无偏倚，标准差约为± 0.5 K。前视图中使用的SW算法导致0.6 K的偏差和plusmn 0.8 K的标准差。在其他算法中获得最差结果，在DA算法的情况下，偏差接近-1.0 K，标准差接近+1.1 K。
A database of global, cloud-free, and atmospheric radiosounding profiles was compiled with the aim of simulating radiometric measurements from satellite-borne sensors in the thermal infrared. The objective of the simulated data is to generate split-window (SW) and dual-angle (DA) algorithms for the retrieval of land surface temperature (LST) from Terra/Moderate Resolution Imaging Spectroradiometer (MODIS) and Envisat/Advanced Along Track Scanning Radiometer (AATSR) data. The database contains 382 radiosounding profiles acquired over land, with nearly uniform distribution of precipitable water between 0.02 and 5.5 cm. Radiative transfer calculations were performed with the MODTRAN 4 code for six viewing angles between 0deg and 60deg. The resulting radiance spectra were convoluted with the response filter functions of MODIS bands 31 and 32 and AATSR channels at 11 and 12 mum. By using the simulation database, the SW algorithms adapted for MODIS and AATSR data and the DA algorithms for AATSR data were developed. Both types of algorithms are quadratic in the brightness temperature difference and depend explicitly on the land surface emissivity. The SW and DA algorithms were validated with actual ground measurements of LST collected concurrently to MODIS and AATSR observations in a site located close to the city of Valencia, Spain, in a large, flat, and thermally homogeneous area of rice crops. The results obtained have no bias and a standard deviation around plusmn0.5 K for the SW algorithms at nadir for both sensors. The SW algorithm used in the forward view results in a bias of 0.6 K and a standard deviation of plusmn0.8 K. The worst results are obtained in the other algorithms with a bias close to -1.0 K and a standard deviation close to plusmn1.1 K in the case of the DA algorithms.