Bathymetry--Drakes Bay and Vicinity, California

This part of DS 781 presents data for the bathymetry and shaded-relief maps of Drakes Bay and Vicinity, California (raster data file is included in "Bathymetry_DrakesBay.zip," which is accessible from http://pubs.usgs.gov/ds/781/DrakesBay/data_catalog_DrakesBay.html. The bathymetry and shaded-relief maps of Drakes Bay and Vicinity, California, were generated from bathymetry data collected by California State University, Monterey Bay (CSUMB), and by Fugro Pelagos. Mapping was completed between 2007 and 2010, using a combination of 200-kHz and 400-kHz Reson 7125, and 244-kHz Reson 8101 multibeam echosounders, as well as 468-kHz SEA SWATHPlus interferometric system. These mapping missions combined to collect bathymetry from about the 10-m isobath to beyond the 3-nautical-mile limit of Californiaís State Waters. NOTE: the horizontal datum of the bathymetry data (NAD83) differs from the horizontal datum of other layers in this data series (WGS84). Some bathymetry grids within this map were projected horizontally from WGS84 to NAD83 using ESRI tools to be more consistent with the vertical reference of the North American Vertical Datum of 1988 (NAVD88). These data are not intended for navigational purposes.

本数据集为DS 781的组成部分，提供加利福尼亚州德雷克湾及其周边区域的水深与晕渲地形图数据，栅格数据文件包含于"Bathymetry_DrakesBay.zip"压缩包中，可通过http://pubs.usgs.gov/ds/781/DrakesBay/data_catalog_DrakesBay.html获取。加利福尼亚州德雷克湾及其周边区域的水深与晕渲地形图由加州州立大学蒙特雷湾分校（California State University, Monterey Bay, CSUMB）与Fugro Pelagos采集的水深数据生成。测绘工作于2007年至2010年间完成，所用设备包括200kHz与400kHz的Reson 7125多波束测深仪（multibeam echosounders）、244kHz的Reson 8101多波束测深仪，以及468kHz的SEA SWATHPlus干涉测深系统（interferometric system）。本次测绘任务共采集了约10米等深线至加州领海3海里以外区域的水深数据。注：本次水深数据的水平基准面为NAD83，与本数据集系列中其他图层的水平基准面WGS84不一致。本地形图中的部分水深网格通过ESRI工具从WGS84水平投影至NAD83，以更贴合1988北美垂直基准面（North American Vertical Datum of 1988, NAVD88）的垂直参考系。本数据集不得用于导航用途。