Near-bottom ROV multibeam bathymetry grid (netCDF format) from the Octopus Garden hydrothermal spring site

Near-bottom high-resolution bathymetry data were collected with a Reson 7125 multibeam sonar that is part of the MBARI Low Altitude Survey System (LASS) mounted for two dives in 2021 to the ROV Doc Ricketts, which was flown at 3 m altitude at speeds <= 1.0 m/s to produce 5 cm-resolution bathymetry grids and images from the multibeam. The grid file presented here is in GMT-compatible netCDF format and the projection is UTM zone 10N. Position and attitude data were provided by a Kearfott SeaDevil Inertial Navigation System (INS) integrated with a 1200 kHz Teledyne RD Instruments Doppler velocity log (DVL) and a Paroscientific pressure sensor. The LASS sensor package was mounted in an articulating frame within an ROV tool sled that rotates from pointing the sensors vertically down to horizontally forward, allowing surveys of flat to vertical seafloor. The articulation is automated by closing a control loop around the difference between the forward and backward beams of the DVL. Funding was provided by a grant from the David and Lucile Packard Foundation to MBARI.

本数据集采用Reson 7125多波束声呐采集近底高分辨率水深数据，该声呐为蒙特利湾水族馆研究所（Monterey Bay Aquarium Research Institute, MBARI）低空测量系统（Low Altitude Survey System, LASS）的组成部分。2021年，该系统搭载于“Doc Ricketts”号遥控无人潜水器（Remotely Operated Vehicle, ROV）完成两次下潜作业，作业时潜水器飞行高度为3米、航速不超过1.0 m/s，由此生成分辨率达5厘米的水深网格与多波束声呐影像。本次提供的网格文件采用兼容通用制图工具（Generic Mapping Tools, GMT）的网络通用数据格式（netCDF），投影坐标系为UTM 10N分带。位置与姿态数据由Kearfott SeaDevil惯性导航系统（Inertial Navigation System, INS）提供，该系统集成了1200 kHz Teledyne RD Instruments多普勒测速仪（Doppler Velocity Log, DVL）与Paroscientific压力传感器。LASS传感器套件安装于遥控无人潜水器工具滑橇的铰接框架内，该框架可使传感器从垂直向下旋转至水平向前，从而实现平坦至垂直海底地形的测量作业。该铰接动作通过闭合多普勒测速仪前后波束的差值控制环路实现自动化。本数据集的研究经费由David和Lucile Packard基金会向蒙特利湾水族馆研究所（MBARI）提供的拨款资助。