Temperature profiles from expendable bathythermograph (XBT) casts from the NOAA Ship FAIRWEATHER in the Gulf of Alaska in support of the Integrated Global Ocean Services System (IGOSS) project from 24 August 1974 to 25 August 1974 (NODC Accession 7400620)

XBT data were collected from the NOAA Ship FAIRWEATHER in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the US DOC; NOAA; National Ocean Service - Seattle from 24 August 1974 to 25 August 1974. 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.

抛弃式海洋深度温度计（expendable bathythermograph, XBT）数据由NOAA Fairweather号科考船采集，以支撑综合全球海洋服务系统（Integrated Global Ocean Services System, IGOSS）项目。数据采集方为美国商务部（US DOC）、美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）以及国家海洋服务局-西雅图分部，采集时段为1974年8月24日至1974年8月25日。数据经国家海洋数据中心（National Oceanographic Data Center, NODC）处理，符合NODC标准的通用海洋深度温度计输出（Universal Bathythermograph Output, UBT）格式。完整格式说明可通过NODC官网www.nodc.noaa.gov/General/NODC-Archive/bt.html获取。

UBT文件格式用于记录由抛弃式海洋深度温度计（XBT）仪器获取的温度-深度剖面数据。标准型XBT可获取约450米或760米深度范围内的剖面数据；搭载专用仪器时，测量深度可达1830米。每条观测记录均附带航次信息、观测位置、日期与时间。数据记录由温度-深度值对组成。与温度以5米均匀间隔记录的机械式海洋深度温度计（MBT）数据文件不同，XBT数据文件中的温度值对应非均匀深度。这些深度点为将温度曲线记录至可接受精度所需的最少点位（即"inflection points"）。不过在输出环节，用户可选择获取拐点处的温度值，或通过插值得到均匀深度增量下的温度值。