sw109sc_video_observations

This part of DS 781 presents video observations from cruise SW109SC for the Santa Barbara Channel region and beyond in southern California. The vector data file is included in "sw109sc_video_observations.zip," which is accessible from http://pubs.usgs.gov/ds/781/video_observations/data_catalog_video_observations.html. Some of the video observations from cruise SW109SC are published in Scientific Investigations Map 3254, "California State Waters Map Series--Offshore of Ventura, California" (see sheet 6). In addition, some of the video observations will be published in six future California State Waters Map Series SIMs of the region (namely, the Offshore of Point Dume, Magu Canyon and Vicinity, Offshore of Coal Oil Point, Offshore of Refugio Beach, Offshore of Gaviota, and Offshore of Point Conception map areas). Between 2006 and 2007, the seafloor in the Offshore of Point Dume, Mugu Canyon and Vicinity, Offshore of Ventura, Offshore of Coal Oil Point, Offshore of Refugio Beach, Offshore of Gaviota, and Offshore of Point Conception map areas in southern California was mapped by California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB) and by the U.S. Geological Survey (USGS), using both multibeam echosounders and bathymetric sidescan sonar units (for example, see sheets 1, 2, and 3, SIM 3254, for details). These mapping missions combined to collect bathymetry and acoustic-backscatter data from about the 10-m isobath to out beyond the 3-nautical-mile limit of California's State Waters. To validate the interpretations of sonar data in order to turn it into geologically and biologically useful information, the USGS ground-truth surveyed the data by towing camera sleds over specific locations throughout the region. During the 2008 ground-truth cruise, the camera sled housed two video cameras (one forward looking and the other vertical looking), a high-definition video camera, and an 8-megapixel digital still camera. The video was fed in real time to the research vessel, where USGS and NOAA scientists recorded both the geologic and biologic character of the seafloor into programmable keypads once every minute. In addition to recording the seafloor characteristics, a digital still photograph was captured once every 30 seconds. This ArcGIS shape file includes the position of the camera, the time each observation was started, and the visual observations of geologic and biologic habitat.本数据集为DS 781的组成部分，包含针对美国加利福尼亚州南部圣巴巴拉海峡及周边海域的SW109SC航次视频观测数据。矢量数据文件存储于"sw109sc_video_observations.zip"压缩包内，可通过http://pubs.usgs.gov/ds/781/video_observations/data_catalog_video_observations.html获取。 SW109SC航次的部分视频观测数据已发表于《科学调查地图集》3254号《加利福尼亚州海域地图系列——加利福尼亚州文图拉近海》（参见第6幅图幅）。此外，该航次的部分视频观测数据将收录于该区域后续推出的6幅《加利福尼亚州海域地图系列》科学调查地图中，分别为：杜姆角近海、马古峡谷及周边区域、科伊尔油点近海、雷富吉海滩近海、加维奥塔近海以及康塞普申角近海的图幅范围。 2006至2007年间，加利福尼亚州立大学蒙特雷湾分校海底测绘实验室（CSUMB）与美国地质调查局（USGS）联合采用多波束测深仪与测深侧扫声呐设备，对加利福尼亚州南部的杜姆角近海、马古峡谷及周边区域、文图拉近海、科伊尔油点近海、雷富吉海滩近海、加维奥塔近海以及康塞普申角近海海域开展海底测绘工作（详细信息参见《科学调查地图集》3254号的第1、2、3幅图幅）。本次测绘任务采集了从约10米等深线至超出加利福尼亚州海域3海里界限范围内的水深数据与声学背散射数据。为验证声呐数据解译结果，将其转化为具备地质与生物学应用价值的信息，美国地质调查局实施了实地勘测验证工作：通过在区域内指定点位拖曳摄像雪橇开展观测。在2008年的实地勘测航次中，摄像雪橇搭载了两台摄像机（一台正向拍摄、一台垂直向下拍摄）、一台高清摄像机以及一台800万像素数码相机。视频信号被实时传输至研究船，美国地质调查局与美国国家海洋和大气管理局（NOAA）的科研人员每一分钟通过可编程按键面板记录一次海底的地质与生物特征。除记录海底特征外，系统还每30秒拍摄一张数码静态照片。本ArcGIS形状文件包含了摄像机的位置信息、每次观测的起始时间，以及地质与生物栖息地的目视观测记录。