US SUHI database

This dataset contains urban and rural LST, DEM, and NDVI data for annual, summer, and winter daytime and nighttime for all census tracts in US urbanized areas, as well as the mean values for the entire urbanized area. METADATA DEM: Digital Elevation Model NDVI: Normalized Difference Vegetation Index LST: Land Surface Temperature _urb: Urban values (all urban pixels within urbanized areas) _rur: Rural reference (Spatial mean of the non-urban, non-water pixels within the region of interest) Regions of Interest: _CT: Spatial mean of pixels intersecting the Census Tract clipped to the urbanized area (one value per census tract). This should be equal to the _CT for census tracts that are completely within the urbanized areas (the census tracts with the green dots in the image below) _all: Spatial mean of all pixels intersecting the urbanized area, as defined by the US census (one value for one urbanized area) _CT_act: Spatial mean of all available pixels intersecting the Census Tract (one value per census tract) [This should be equal to the previous values I calculated] For the UHI: The ideal configuration is LST_urb_all-LST_rur_all for the entire urbanized area (from the US_Urbanized file) and LST_urb_CT_act-LST_rur_all for individual census tracts within the urbanized areas (from the census file) For the equity analysis: Either _CT or CT_act can be used if we are only concerned with spatial variation. Using CT_act leads to mismatch between census data for the tracts crossing the urban boundary and the remotely sensed data. Using _CT leads to mismatch between the UHI analysis and the equity analysis.本数据集包含美国城市化区域内所有普查区的年度、夏季、冬季昼间与夜间城乡地表温度（Land Surface Temperature, LST）、数字高程模型（Digital Elevation Model, DEM）及归一化植被指数（Normalized Difference Vegetation Index, NDVI）数据，同时涵盖对应城市化区域的全域均值。 元数据说明： DEM：数字高程模型 NDVI：归一化植被指数 LST：地表温度 _urb：城镇值（城市化区域内全部城镇像元） _rur：乡村参照值（研究区域内非城镇、非水域像元的空间均值） 研究区域定义如下： _CT：裁剪至城市化区域内、与普查区相交的像元空间均值（每个普查区对应一个取值）。对于完全位于城市化区域内的普查区（即下图中带有绿色点的普查区），该取值应与_CT_act一致。 _CT_act：与普查区相交的全部可用像元的空间均值（每个普查区对应一个取值）[该取值应与我此前计算的前述数值一致] _all：美国人口普查局定义的、与城市化区域相交的全部像元的空间均值（每个城市化区域对应一个取值） 针对热岛效应（Urban Heat Island, UHI）分析，理想配置为：针对全域城市化区域（源自US_Urbanized文件），采用LST_urb_all - LST_rur_all；针对城市化区域内的单个普查区（源自普查文件），采用LST_urb_CT_act - LST_rur_all。 针对公平性分析，若仅关注空间变异，可选用_CT或_CT_act。使用_CT_act会导致跨越城市边界的普查区的普查数据与遥感数据不匹配；使用_CT则会导致热岛效应分析与公平性分析之间出现不一致。