OCS Gulf NAD27 Protraction Polygons - 1st Division

These data contain a Gulf OCS Region NAD27 scale spatial footprint of the outer boundaries of the Bureau of Ocean Energy Management’s (BOEM’s) Official Protraction Diagrams (OPDs) and Leasing Maps (LMs). These polygons are clipped to the Submerged Land Act Boundary and Continental Shelf Boundaries and are updated as needed. OPDs are mapping products produced and used by the BOEM to delineate areas available for potential offshore mineral leases, determine the State/Federal offshore boundaries, and determine the limits of revenue sharing and other boundaries to be considered when leasing offshore waters. The OPDs serve as the legal definition for BOEM offshore boundary coordinates and area descriptions. These data show only the outline of the maps that are available from BOEM. Only the most recently published paper or pdf versions of the OPDs should be used for official or legal purposes. Further information on the history of the development of OPDs can be found in OCS Report MMS 99-0006: Boundary Development on the Outer Continental Shelf. These data were created in the applicable NAD83 UTM or NAD27 UTM/SPCS Projection and re-projected to GCS WGS84 (EPSG 4326) for management in BOEM's enterprise GIS. Because GIS projection and topology functions can change or generalize coordinates, these data are NOT an OFFICIAL record for the exact boundaries. These data are to be used for Cartographic purposes only and should not be used to calculate area.本数据集包含墨西哥湾外大陆架（Outer Continental Shelf, OCS）区域采用北美大地基准面1927（North American Datum 1927, NAD27）的空间范围数据，对应美国海洋能源管理局（Bureau of Ocean Energy Management, BOEM）官方标定图（Official Protraction Diagrams, OPDs）与租赁地图（Leasing Maps, LMs）的外边界。该类多边形要素已依据《淹没土地法》边界与大陆架边界进行裁切，并将按需更新。OPDs为美国海洋能源管理局编制并使用的制图产品，用于划定可开展海上矿产租赁的潜在区域、明确州级与联邦级海上边界，以及确定海上水域租赁时需考量的收益分配限额与其他相关边界。OPDs是美国海洋能源管理局海上边界坐标与面积描述的法定界定依据。本数据集仅展示可从美国海洋能源管理局获取的地图轮廓。仅可使用OPDs最新发布的纸质版或PDF版文件，作为官方或法定用途的合规依据。关于OPDs开发历史的更多详细信息，可参阅外大陆架报告《OCS Report MMS 99-0006：外大陆架边界划定》。本数据集最初采用适配的北美大地基准面1983（North American Datum 1983, NAD83）通用横轴墨卡托投影（Universal Transverse Mercator, UTM），或北美大地基准面1927 UTM/州平面坐标系统（State Plane Coordinate System, SPCS）构建，后重新投影至大地坐标系统WGS84（EPSG 4326），以适配美国海洋能源管理局企业地理信息系统的管理需求。由于地理信息系统的投影与拓扑功能可能会改变或简化坐标信息，本数据集并非精确边界的官方备案文件。本数据集仅可用于制图用途，不得用于面积计算。