Video-OCS Floating Wind Farm Site

This data release contains digital video files from the USGS field activity 2014-607-FA, a survey of the Oregon Outer Continental Shelf (OCS) Floating Wind Farm Site in 2014. Video data were collected over 3 days between September 6 and September 9, 2014 using a towed camera sled system. 11.6 hours of video were collected along 18 transects; the mean length of time per transect was 38 minutes. Video operations were conducted by deploying up drift of a target and drifting over it at speeds of 1 knot or slower. The video data were collected in order to ground truth geologic and habitat interpretations of sonar data collected during the same field activity. The video-survey locations were chosen after the sonar mapping to investigate sea-floor features of interest, including bathymetric features such as ridges and depressions, areas that represent the spectrum of backscatter intensity observed in the survey area, and areas that represent the spectrum of water depths surveyed. The camera sled was equipped with both vertical-downward and adjustable oblique-forward facing HD video cameras. Paired lasers set a fixed distance apart are visible in the video and are used to scale features on the seafloor. A fiber optic cable was used to allow real-time on-board viewing of both camera feeds. The sled was also equipped with a forward-scanning sonar system for collision avoidance. Conductivity and temperature were continuously recorded using a SeaBird Seacat 37-SM. Depth and altitude were measured to aid operations but not recorded. A downward facing still camera, designed for small invertebrate identification, was attached to the sled, but insufficient lighting rendered the still images unusable. Real-time observations of the major and minor substrate type were made, as well as occasional comments about organisms, features, or objects of interest.

本数据集发布内容包含美国地质调查局（U.S. Geological Survey, USGS）野外作业项目2014-607-FA的数字视频文件，该项目为2014年俄勒冈州外大陆架（OCS, Outer Continental Shelf）漂浮风电场场址的勘测活动。本次勘测于2014年9月6日至9月9日的3个作业日内完成，采用拖曳式摄像雪橇系统采集视频数据，共沿18条测线采集了11.6小时的视频数据，单条测线的平均采集时长为38分钟。视频采集作业通过将摄像雪橇布设于目标区域的上风侧，并以1节及以下的速度沿风流驶过目标区域完成。本次视频数据采集的核心目的是为同一野外作业中获取的声呐数据的地质与生境解译提供地面真值（ground truth）验证。视频勘测点位于声呐测绘完成后选定，用于调查目标海底特征：包括海脊、海洼等水深地形特征，覆盖勘测区域观测到的反向散射强度全区间的区域，以及覆盖勘测区域水深全区间的区域。该拖曳摄像雪橇搭载了垂直向下和可调节斜向前的高清（HD）摄像机。视频画面中可见一对间距固定的配对激光，用于对海底特征进行尺度标定。通过光纤电缆可实现两路摄像机画面的实时船端观看。该雪橇还搭载了前视声呐系统，用于防撞避险。作业中采用SeaBird Seacat 37-SM型设备连续记录电导率与温度数据。水深与高度数据仅用于辅助作业，未进行存储记录。雪橇上还加装了一台垂直向下的静态相机，用于小型无脊椎动物的识别，但因光照不足，拍摄的静态图像无法使用。作业人员同时对底质类型的主次类别进行了实时记录，并对观测到的目标生物、特征或物体做出了零星备注。