Tree Canopy Cover (TCC) Science Standard Error (SE) Hawaii

The USDA Forest Service (USFS) builds two versions of percent tree canopy cover data, in order to serve needs of multiple user communities. These datasets encompass conterminous United States (CONUS), Coastal Alaska, Hawaii, and Puerto Rico and U.S. Virgin Islands (PRUSVI). The two versions of data within the v2021-4 TCC product suite include: The initial model outputs referred to as the Science data; And a modified version built for the National Land Cover Database and referred to as NLCD data. The Science data are the initial annual model outputs that consist of two images: percent tree canopy cover (TCC) and standard error. These data are best suited for users who will carry out their own detailed statistical and uncertainty analyses on the dataset, and place lower priority on the visual appearance of the dataset for cartographic purposes. Datasets for the years 2008 through 2021 are available. The Science data were produced using a random forests regression algorithm. For standard error data, the initial standard error estimates that ranged from 0 to approximately 45 were multiplied by 100 to maintain data precision (e.g., 45 = 4500). Therefore, standard error estimates pixel values range from 0 to approximately 4500. The value 65534 represents the non-processing area mask where no cloud or cloud shadow-free data are available to produce an output, and 65535 represents the background value. The Science data are accessible for multiple user communities, through multiple channels and platforms. For information on the NLCD TCC data and processing steps see the NLCD metadata. Information on the Science data and processing steps are included here. Data Download and Methods Documents: - https://data.fs.usda.gov/geodata/rastergateway/treecanopycover/美国农业部森林服务局（USDA Forest Service, USFS）开发了两个版本的树木冠层覆盖率百分比数据，以满足多类用户群体的需求。本数据集覆盖美国本土（conterminous United States, CONUS）、阿拉斯加沿海地区、夏威夷以及波多黎各和美属维尔京群岛（PRUSVI）。 v2021-4 TCC产品套件包含两个数据版本：一是被称为科学数据的初始模型输出结果；二是为美国国家土地覆盖数据库（National Land Cover Database）开发的改良版本，即NLCD数据。 科学数据为初始年度模型输出结果，包含两幅影像：树木冠层覆盖率百分比（percent tree canopy cover, TCC）数据与标准误差（standard error）数据。该类数据最适合需要自行开展精细化统计与不确定性分析、且对制图用途下的数据视觉外观优先级较低的用户。数据集涵盖2008年至2021年的年度数据。 科学数据采用随机森林回归算法生成。针对标准误差数据，初始范围为0至约45的标准误差估计值被乘以100以保留数据精度（例如，原数值45对应处理后为4500），因此标准误差数据的像素值范围为0至约4500。其中，数值65534代表无云或无云阴影数据可用于生成输出的非处理区域掩码，65535代表背景值。 科学数据可通过多渠道与平台面向多类用户群体开放获取。有关NLCD TCC数据及其处理步骤的信息，请参阅NLCD元数据（metadata）。有关科学数据及其处理步骤的信息已包含在本文档中。 数据下载与方法文档：- https://data.fs.usda.gov/geodata/rastergateway/treecanopycover/