LandScanUSA

Purpose: To provide essential foundation-level high resolution spatial population distribution data for use in directsupport of the Homeland Security, Homeland Defense, and Emergency Response and Recovery missions to protect the nation's infrastructure in accordance with Presidential Policy Directive-8: National Preparedness (PPD-8), PPD-21: Critical Infrastructure Security and Resilience, and the National Strategy for Physical Protection of Critical Infrastructure and Key Assets.Data Values: The values of the cells are integer population counts representing either the daytime or nighttime estimated population distribution. LandScan USA employs sub-models for different population components (residents, workers, prisoners, students, shoppers). Each sub-model begins with observed or estimated population counts for a defined area. The populations are redistributed to raster cells according to the relationship between spatial ancillary layers and population density. The ‘Value’ field in the database table refers to the estimated population in a cell, while the ‘Count’ field references the number of cells in the grid having that Value. Learn more about LandScan at https://LandScan.ornl.gov.This document is current as of July 27 2021Features and BenefitsUse: Allows quick and easy assessment, estimation, and visualization of population.Coverage Area: LandScan USA for Nighttime and Day-time, for the continental United States, Alaska (AK), and Hawaii (HI) and the U.S. Territories of Puerto Rico (PR), U.S. Virgin Islands (VI), Guam (GU), Northern Mariana Islands (MP), and American Samoa (AS).Metadata: Includes the Federal Geographic Data Committee (FGDC) Metadata Standard as specified at: https://www.fgdc.gov/metadata/csdgm-standardLandScan USAhttps://landscan.ornl.gov/

目的：本数据集旨在提供基础级高分辨率空间人口分布数据，以直接支持国土安全、国土防御以及应急响应和恢复任务，旨在保护国家基础设施，符合《总统政策指令-8：国家准备》（PPD-8）、《总统政策指令-21：关键基础设施安全与韧性》（PPD-21）以及《关键基础设施和重要资产物理保护国家战略》。数据值：单元格的数值为整数，代表日间或夜间估计的人口分布。LandScan USA采用子模型来处理不同的人口组成部分（居民、工作者、囚犯、学生、购物者）。每个子模型均以定义区域内观察或估计的人口计数开始。根据空间辅助层与人口密度的关系，将这些人口重新分配到栅格单元中。数据库表中的‘Value’字段指代单元格中的估计人口，而‘Count’字段则指代网格中具有该数值的单元格数量。更多关于LandScan的信息请访问https://LandScan.ornl.gov。本文件截至2021年7月27日。功能和优势：使用本数据集可快速、便捷地评估、估计和可视化人口分布。覆盖范围：LandScan USA夜间和日间数据，涵盖美国大陆、阿拉斯加（AK）、夏威夷（HI）以及美属波多黎各（PR）、美属维尔京群岛（VI）、关岛（GU）、北马里亚纳群岛（MP）和美国萨摩亚（AS）等美国领土。元数据：包括联邦地理数据委员会（FGDC）元数据标准，具体见：https://www.fgdc.gov/metadata/csdgm-standard。LandScan USA，https://landscan.ornl.gov。