Bathymetry Hillshade--Offshore of Santa Barbara, California

This part of SIM 3281 presents data for the bathymetry and shaded-relief maps (see sheets 1, 2, SIM 3281) of the Offshore of Santa Barbara map area, California. The raster data file for the bathymetry map is included in "Bathymetry_OffshoreSantaBarbara.zip." The raster data file for the shaded-relief map is included in "BathymetryHS_OffshoreSantaBarbara.zip." Both are accessible from http://pubs.usgs.gov/ds/781/OffshoreSantaBarbara/data_catalog_OffshoreSantaBarbara.html.
The bathymetry and shaded-relief maps of the Offshore of Santa Barbara map area, California, were generated from bathymetry data collected by California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB), by the U.S. Geological Survey (USGS), and by Fugro Pelagos for the U.S. Army Corps of Engineers (USACE) Joint Lidar Bathymetry Technical Center of Expertise. Most of the offshore area was mapped by CSUMB in the summer of 2007, using a 244-kHz Reson 8101 multibeam echosounder. Smaller areas in the far-east nearshore, as well as further offshore to the west and in the southeast outer shelf area, were mapped by the USGS in 2005 and 2006, using a combination of 468-kHz (2005) and 117-kHz (2006) SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonars. The nearshore bathymetry and coastal topography were mapped for USACE by Fugro Pelagos in 2009, using the SHOALS-1000T bathymetric-lidar and Leica ALS60 topographic-lidar systems. All these mapping missions combined to collect bathymetry from the 0-m isobath to beyond the 3-nautical-mile limit of California's State Waters. NOTE: The horizontal datum of this bathymetry data (NAD83) differs from the horizontal datum of other layers in this SIM (WGS84). Some bathymetry grids within this map area 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).

本数据集隶属于SIM 3281系列，包含加利福尼亚州圣巴巴拉近海制图区的水深测量图与晕渲地形图数据（详见SIM 3281图集第1、2幅图）。其中水深测量图的栅格数据文件收录于"Bathymetry_OffshoreSantaBarbara.zip"，晕渲地形图的栅格数据文件收录于"BathymetryHS_OffshoreSantaBarbara.zip"，二者均可通过链接 http://pubs.usgs.gov/ds/781/OffshoreSantaBarbara/data_catalog_OffshoreSantaBarbara.html 获取。

圣巴巴拉近海的水深与晕渲地形数据源自三家机构的采集成果：加州州立大学蒙特利湾分校海底测绘实验室（CSUMB）、美国地质调查局（USGS），以及为美国陆军工程兵团（USACE）联合激光雷达测深技术专家中心服务的辉固佩拉戈斯（Fugro Pelagos）公司。
1. 绝大部分近海区域由CSUMB于2007年夏季完成测绘，采用244kHz Reson 8101多波束测深仪；
2. 东部近岸小范围区域、西部远岸区域以及东南部外陆架区域，由USGS分别于2005年、2006年完成测绘，2005年使用468kHz SEA (AP) Ltd. SWATHplus-M相位差分侧扫声呐，2006年升级使用117kHz同款设备；
3. 近岸水深与海岸地形数据，由Fugro Pelagos公司于2009年为USACE完成测绘，采用SHOALS-1000T测深激光雷达与Leica ALS60地形激光雷达系统。

上述所有测绘任务的覆盖范围均从0米等深线延伸至加州州立海域3海里以外海域。

注意：本数据集水深数据的水平基准为NAD83，与本SIM系列中其他图层采用的WGS84水平基准存在差异。制图区内部分水深栅格数据已通过ESRI工具从WGS84投影转换至NAD83，以匹配1988年北美垂直基准面（NAVD88）的垂直参考系。