Single-Beam Bathymetry Data Collected in 2015 nearshore Dauphin Island, Alabama, U.S. Geological Survey (USGS). This metadata file is specific to the International Reference Frame 2000 (ITRF00) xyz point data.

Dauphin Island, Alabama is a barrier island located in the Gulf of Mexico that supports local residence, tourism, commercial infrastructure, and the historical Fort Gaines. During the past decade the island has been impacted by several major hurricanes (Ivan, 2004; Katrina, 2005; Isaac 2012). Storms along with sea level rise, presents a continued threat to island stability. State and federal managers are taking a scientific investigative approach to identify the best options available to formulate and implement a long-term plan to properly restore Dauphin Island and provide resilience against future storms and sea-level rise. Island morphology, including current bathymetry data, is one of several aspects being investigated and funded through a grant from National Fish and Wildlife Foundation Gulf Environmental Benefit Fund. In August 2015, the United States Geological Survey Saint Petersburg Coastal and Marine Science Center (USGS SPCMSC) in cooperation with the United States Army Corps of Engineers (USACE) and the state of Alabama conducted bathymetric surveys of the nearshore waters surrounding Dauphin Island. This data release provides 1,165-line kilometers (km) of processed single-beam bathymetry (SBB) data collected by the USGS SPCMSC in August 2015 (Field Activity Number [FAN] 2015-326-FA). Data were acquired aboard 4 separate survey vessels; the RV Sallenger (subFAN, 15BIM10), the RV Jabba Jaw (subFAN, 15BIM11), the RV Shark (subFAN, 15BIM12), and the RV Chum (subFAN, 15BIM13). The data are provided in three datums: 1) the International Terrestrial Reference Frame of 2000 (ITRF00), ellipsoid height (-47.04 meters [m] to -29.36 m); 2) the North American Datum of 1983, realization of CORS96 (NAD83 (CORS96)) horizontal, and the North American Vertical Datum 1988 (NAVD88) vertical (-0.24 m to -17.33 m); and 3) the NAD83 (CORS96) horizontal, and Mean Lower Low Water (MLLW) vertical (-0.12 m to -17.93 m). Additional files include trackline shapefiles, digital and handwritten Field Activity Collection Systems (FACS) logs, a comprehensive 50-meter Digital Elevation Model (DEM), and formal Federal Geographic Data Committee (FGDC) metadata.

阿拉巴马州多芬岛（Dauphin Island）是坐落于墨西哥湾的障壁岛（barrier island），该岛承载着当地居民生活、旅游业发展、商业基础设施运营，同时留存有历史悠久的盖恩斯堡（Fort Gaines）遗址。近十年来，该岛先后遭受多场强飓风袭击（2004年伊凡飓风、2005年卡特里娜飓风、2012年艾萨克飓风）。风暴灾害叠加海平面上升，持续对岛屿的稳定性构成威胁。州与联邦管理部门正采用科学调研方法，遴选最优方案以制定并实施长期修复计划，助力多芬岛实现有效修复，并提升其抵御未来风暴与海平面上升的韧性。岛屿地貌（包含当前水深测量数据）是多项调研内容之一，该项目由国家鱼类和野生动物基金会海湾环境效益基金（National Fish and Wildlife Foundation Gulf Environmental Benefit Fund）拨款资助。2015年8月，美国地质调查局圣彼得堡海岸与海洋科学中心（USGS SPCMSC）联合美国陆军工程兵团（USACE）与阿拉巴马州政府，对多芬岛周边近岸海域开展了水深测量作业。本数据集发布包含2015年8月由USGS SPCMSC采集的经处理后的单波束水深测量（single-beam bathymetry, SBB）数据，总长度达1165线公里（km），对应野外活动编号（Field Activity Number, FAN）为2015-326-FA。本次数据采集共动用4艘测量船：萨伦杰号科考船（RV Sallenger，子活动编号15BIM10）、贾巴乔号科考船（RV Jabba Jaw，子活动编号15BIM11）、沙克号科考船（RV Shark，子活动编号15BIM12）以及查姆号科考船（RV Chum，子活动编号15BIM13）。本次数据采用三种基准发布：1）2000年国际地面参考框架（ITRF00），椭球高范围为-47.04米至-29.36米；2）1983年北美大地基准（CORS96实现版，NAD83 (CORS96)）水平基准，以及1988年北美垂直基准（NAVD88）垂直基准，垂直范围为-0.24米至-17.33米；3）NAD83 (CORS96)水平基准，以及平均低低潮面（MLLW）垂直基准，垂直范围为-0.12米至-17.93米。附带文件包括测线形状文件、数字化与手写版野外活动采集系统（Field Activity Collection Systems, FACS）日志、完整的50米分辨率数字高程模型（Digital Elevation Model, DEM），以及符合联邦地理数据委员会（Federal Geographic Data Committee, FGDC）标准的正式元数据。