k291bg.m77t and k291bg.h77t: MGD77T data and header files for single-beam bathymetry data for field activity K-2-91-BG in Bering Glacier, Alaska from 07/02/1991 to 07/06/1991

Single-beam bathymetry data along with radar and GPS navigation data was collected as part of the U.S. Geological Survey cruise K-2-91-BG. The cruise was conducted in Bering Glacier, Alaska from July 2 to July 6, 1991. The chief scientists were Paul Carlson from the USGS Coastal and Marine Geology office in Menlo Park, CA.
The overall purpose of this study is to collect bathymetry, sidescan and samples from Icy Bay to Vitus Lake, Alaska. The geophysical source is 7 kilohertz (kHz) and 3.5 kHz systems.
These data are reformatted from space-delimited ASCII text files located in the Coastal and Marine Geology Program (CMGP) InfoBank field activity catalog at http://walrus.wr.usgs.gov/infobank/k/k191yb/html/k-1-91-yb.meta.html into MGD77T format provided by the NOAA's National Geophysical Data Center(NGDC). The MGD77T format includes a header (documentation) file (.h77t) and a data file (.m77t). More information regarding this format can be found in the publication listed in the Cross_reference section of this metadata file.

本数据集包含单波束测深数据（single-beam bathymetry data）以及雷达与GPS导航数据，采集自美国地质调查局（U.S. Geological Survey, USGS）航次K-2-91-BG。该航次于1991年7月2日至7月6日在阿拉斯加州白令冰川（Bering Glacier）海域开展，首席科学家为来自加州门洛帕克市USGS海岸与海洋地质办公室的保罗·卡尔森（Paul Carlson）。
本研究的整体目标为采集阿拉斯加州冰湾（Icy Bay）至维图斯湖（Vitus Lake）区域的测深数据、侧扫声呐（sidescan）数据与沉积物样品，所用地球物理声源系统为7千赫兹（kHz）与3.5千赫兹（kHz）频段设备。
本次数据源自海岸与海洋地质计划（Coastal and Marine Geology Program, CMGP）信息库野外活动目录（网址：http://walrus.wr.usgs.gov/infobank/k/k191yb/html/k-1-91-yb.meta.html）中的空格分隔ASCII文本文件，现已被转换为美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）下属国家地球物理数据中心（National Geophysical Data Center, NGDC）发布的MGD77T格式。MGD77T格式包含头文件（说明文档，后缀为.h77t）与数据文件（后缀为.m77t）。有关该格式的更多细节，可查阅本元数据文件“交叉参考”部分所列的相关出版物。