Bathymetry--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（SIM 3281）的此部分包含美国加利福尼亚州圣巴巴拉近海制图区的水深测量（bathymetry）图与晕渲地形图（shaded-relief maps）相关数据，详见SIM 3281第1、2幅图幅。
水深测量图的栅格数据文件存储于"Bathymetry_OffshoreSantaBarbara.zip"压缩包中，晕渲地形图的栅格数据文件则存储于"BathymetryHS_OffshoreSantaBarbara.zip"压缩包中。两类数据均可通过http://pubs.usgs.gov/ds/781/OffshoreSantaBarbara/data_catalog_OffshoreSantaBarbara.html获取。

本次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，基于三类数据源制作：加州州立大学蒙特雷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）联合激光测水深技术专家中心服务的富古佩拉戈斯公司（Fugro Pelagos）采集的水深数据。
该制图区的大部分近海区域由CSUMB于2007年夏季采用244kHz Reson 8101多波束测深仪完成测绘。远东近岸、西部远海以及东南外陆架区域的小片区域，则由USGS分别于2005年和2006年，采用468kHz（2005年）与117kHz（2006年）型号的SEA（AP）有限公司SWATHplus-M相位差分旁侧声呐完成测绘。针对USACE的近岸水深测量与海岸地形测绘任务由Fugro Pelagos于2009年完成，所用设备为SHOALS-1000T水深激光雷达与Leica ALS60地形激光雷达系统。
上述所有测绘任务共采集了从0米等深线至超出加利福尼亚州海域3海里边界的水深数据。

注意：本次水深数据采用的水平基准面为北美大地基准1983（NAD83），与本SIM数据集其他图层所用的世界大地测量系统1984（WGS84）水平基准面不一致。制图区内部分水深栅格已通过环境系统研究所（ESRI）工具从WGS84水平基准投影至NAD83，以更好匹配1988年北美垂直基准面（NAVD88）的垂直参考系。