ESA Land Surface Temperature Climate Change Initiative (LST_cci): Multisensor Infra-Red (IR) Low Earth Orbit (LEO) and Geostationary Earth Orbit (GEO) land surface temperature (LST) level 3 supercollated (L3S) global product (2009-2020), version 1.00

This dataset contains land surface temperatures (LSTs) and their uncertainty estimates from multiple Infra-Red (IR) instruments on satellites in Geostationary Earth Orbit (GEO) and Low Earth Orbiting (LEO) sun-synchronous (a.k.a. polar orbiting) satellites. Satellite land surface temperatures are skin temperatures, which means, for example, the temperature of the ground surface in bare soil areas, the temperature of the canopy over forests, and a mix of the soil and leaf temperature over sparse vegetation. The skin temperature is an important variable when considering surface fluxes of, for instance, heat and water. LST fields are provided at 3 hourly intervals each day (00:00 UTC, 03:00 UTC, 06:00 UTC, 09:00 UTC, 12:00 UTC, 15:00 UTC, 18:00 UTC and 21:00 UTC). Per pixel uncertainty estimates are given in two forms, first, an estimate of the total uncertainty for the pixel and second, a breakdown of the uncertainty into components by correlation length. Also provided in the files, on a per pixel basis, are the observation time, the satellite viewing and the solar geometry angles. The product is based on merging of available GEO data and infilling with available LEO data outside of the GEO discs. Inter-instrument biases are accounted for by cross-calibration with the IASI instruments on METOP and LSTs are retrieved using a Generalised Split Window algorithm from all instruments. As data towards the edge of the GEO disc is known to have greater uncertainty, any datum with a satellite zenith angle of more than 60 degrees is discarded. All LSTs included have an observation time that lies within +/- 30 minutes of the file nominal Universal Time. Data from the following instruments is included in the dataset: geostationary, Imagers on Geostationary Operational Environmental Satellite (GOES) 12 and GOES 13, Advanced Baseline Imager (ABI) on GOES 16, Spinning Enhanced Visible Infra-Red Imager (SEVIRI) on Meteosat Second Generation (MSG) 1, MSG 2, MSG 3, and MSG 4, Japanese Advanced Meteorological Imager (JAMI) on Multifunctional Transport Satellite MTSAT) 1, and MTSAT 2; and polar, Advanced Along-Track Scanning Radiometer (AATSR) on Environmental Satellite (Envisat), Moderate-resolution Imaging Spectroradiometer (MODIS) on Earth Observation System (EOS) - Aqua and EOS - Terra, Sea and Land Surface Temperature Radiometer SLSTR on Sentinel-3A and Sentinel-3B. However, it should be noted that which instruments contribute to a particular product file depends on depends on mission start and end dates and instrument downtimes. Dataset coverage starts on 1st January 2009 and ends on 31st December 2020. LSTs are provided on a global equal angle grid at a resolution of 0.05° longitude and 0.05° latitude. The dataset coverage is nominally global over the land surface but varies depending on satellite and instrument availability and coverage. Furthermore, LSTs are not produced where clouds are present since under these circumstances the IR radiometer observes the cloud top which is usually much colder than the surface. The dataset was produced by the University of Leicester (UoL) and data were processed in the UoL processing chain. The Geostationary data were produced by the Instituto Português do Mar e da Atmosfera (IPMA) before being merged into the final dataset. The dataset was produced as part of the ESA Land Surface Temperature Climate Change Initiative which strives to improve satellite datasets to Global Climate Observing System (GCOS) standards.

本数据集包含地表温度（Land Surface Temperatures, LSTs）及其不确定性估计值，数据来源于地球静止轨道（Geostationary Earth Orbit, GEO）及近地轨道（Low Earth Orbiting, LEO）太阳同步（又称极轨）卫星搭载的红外（Infra-Red, IR）仪器。
卫星反演的地表温度即为表皮温度，具体而言，裸土区域对应地表温度、森林区域对应冠层温度，稀疏植被区域则为土壤与叶片温度的混合值。表皮温度是研究地表热通量、水通量等过程的关键变量。
数据集每日以3小时间隔提供地表温度场数据，对应时刻分别为协调世界时（Universal Time Coordinated, UTC）00:00、03:00、06:00、09:00、12:00、15:00、18:00及21:00。
逐像元的不确定性估计包含两种形式：一是该像元的总不确定性估计值，二是按相关长度分解的不确定性分量。
数据文件中还逐像元提供了观测时刻、卫星观测几何角与太阳几何角。
该产品基于融合现有地球静止轨道卫星数据，并在地球静止卫星扫描圆盘之外的区域采用近地轨道卫星数据进行空间填充生成。
通过与METOP卫星搭载的IASI仪器开展交叉定标，消除不同仪器间的系统偏差；所有仪器的地表温度均通过广义分裂窗算法（Generalised Split Window algorithm）反演得到。
由于地球静止卫星扫描圆盘边缘的数据不确定性更高，因此剔除所有卫星天顶角大于60°的观测数据。
所有纳入数据集的地表温度观测时刻，均与数据文件的标称协调世界时偏差不超过±30分钟。
数据集涵盖以下仪器的观测数据：
1. 地球静止轨道仪器：地球静止环境业务卫星（Geostationary Operational Environmental Satellite, GOES）12号与13号搭载的成像仪、GOES 16号搭载的先进基线成像仪（Advanced Baseline Imager, ABI）、Meteosat第二代（Meteosat Second Generation, MSG）1至4号搭载的旋转增强型可见红外成像仪（Spinning Enhanced Visible Infra-Red Imager, SEVIRI）、多功能运输卫星（Multifunctional Transport Satellite, MTSAT）1号与2号搭载的日本先进气象成像仪（Japanese Advanced Meteorological Imager, JAMI）；
2. 极轨轨道仪器：环境卫星（Environmental Satellite, Envisat）搭载的先进沿轨扫描辐射计（Advanced Along-Track Scanning Radiometer, AATSR）、地球观测系统（Earth Observation System, EOS）Aqua与Terra卫星搭载的中分辨率成像光谱辐射计（Moderate-resolution Imaging Spectroradiometer, MODIS）、Sentinel-3A与Sentinel-3B搭载的海陆表面温度辐射计（Sea and Land Surface Temperature Radiometer, SLSTR）。
但需注意，单个产品文件所包含的仪器数据，取决于对应任务的起止日期及仪器停机状态。
数据集的时间覆盖范围为2009年1月1日至2020年12月31日。
地表温度数据以全球等角网格形式提供，空间分辨率为经度0.05°、纬度0.05°。
数据集名义上覆盖全球陆地区域，但实际覆盖范围会随卫星及仪器的可用情况发生变化。
此外，存在云覆盖的区域不会生成地表温度数据，因为此时红外辐射计观测的是云顶温度，通常远低于地表温度。
本数据集由莱斯特大学（University of Leicester, UoL）生成，数据处理流程采用UoL自研的处理链。
地球静止轨道卫星数据由葡萄牙海洋与大气研究所（Instituto Português do Mar e da Atmosfera, IPMA）生成，随后被整合至最终数据集中。
本数据集是欧洲空间局（European Space Agency, ESA）地表温度气候变化倡议（Land Surface Temperature Climate Change Initiative）的研究成果之一，该倡议旨在将卫星数据集提升至全球气候观测系统（Global Climate Observing System, GCOS）标准。