Temperature profiles from expendable bathythermograph (XBT) casts from NOAA Ship MILLER FREEMAN and USS O'BANNON in the North Atlantic Ocean and North Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 1984-02-04 to 1984-02-28 (NODC Accession 8400054)

XBT data were collected from NOAA Ship MILLER FREEMAN and USS O'BANNON in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the National Ocean Service (NOS) and US Navy; Ships of Opportunity from 04 February 1984 to 28 February 1984. Data were processed by NODC to the NODC standard Universal Bathythermograph Output (UBT) format. Full format description is available from NODC at www.nodc.noaa.gov/General/NODC-Archive/bt.html.

The UBT file format is used for temperature-depth profile data obtained using expendable bathythermograph (XBT) instruments. Standard XBTs can obtain profiles at depths of about 450 or 760 m. With special instruments, measurements can be obtained to 1830 m. Cruise information, position, date, and time are reported for each observation. The data record comprises pairs of temperature-depth values. Unlike the MBT data file, in which temperature values are recorded at uniform 5m intervals, the XBT Data File contains temperature values at non-uniform depths. These depths are at a minimum number of points ("inflection points") required to record the temperature curve to an acceptable degree of accuracy. On output, however, the user may request temperature values either at inflection points or interpolated to uniform depth increments.

本数据集的XBT（expendable bathythermograph，一次性投放式海水温度剖面仪）数据采集自NOAA米勒·弗里曼号科考船与美国海军奥班农号驱逐舰，服务于全球海洋综合服务系统（Integrated Global Ocean Services System, IGOSS）项目。数据由美国国家海洋服务局（National Ocean Service, NOS）与美国海军于1984年2月4日至1984年2月28日期间，通过志愿观测船舶采集。美国国家海洋数据中心（National Oceanographic Data Center, NODC）已将数据处理为符合其标准的通用深度温度计输出（Universal Bathythermograph Output, UBT）格式。完整格式说明可通过NODC官方网站www.nodc.noaa.gov/General/NODC-Archive/bt.html查阅。

UBT文件格式用于存储通过XBT仪器获取的温度-深度剖面数据。标准型XBT可获取最大深度约450米或760米的温度剖面；若配备专用仪器，测量深度可达1830米。每份观测记录均包含航次信息、观测位置、观测日期与时间。数据记录由多组温度-深度值对构成。与机械式深度温度计（MBT）数据文件采用均匀5米间隔记录温度值不同，XBT数据文件中的温度值对应非均匀分布的深度。这些深度点为以可接受精度记录温度曲线所需的最少关键点（“拐点”）。但在数据输出环节，用户可选择按原始拐点提取温度值，或通过插值得到均匀深度增量下的温度数据。