Temperature profiles from expendable bathythermograph (XBT) casts from the NOAA Ship RAINIER in the Coastal Waters of SE Alaska/British Columbia in support of the Integrated Global Ocean Services System (IGOSS) project from 22 June 1976 to 25 June 1976 (NODC Accession 7601374)

XBT data were collected from the NOAA Ship Rainier in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the National Ocean Service (NOS) from 22 June 1976 to 25 June 1976. 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.

XBT数据由美国国家海洋和大气管理局“雷恩”号科考船（NOAA Ship Rainier）采集，用于支持综合全球海洋服务系统（Integrated Global Ocean Services System, IGOSS）项目。数据由美国国家海洋服务处（National Ocean Service, NOS）于1976年6月22日至1976年6月25日期间采集，随后由国家海洋数据中心（National Oceanographic Data Center, NODC）处理为NODC标准通用海洋测温仪输出（Universal Bathythermograph Output, UBT）格式。完整格式说明可通过NODC官网获取：www.nodc.noaa.gov/General/NODC-Archive/bt.html。
UBT文件格式用于存储通过抛弃式深海测温仪（expendable bathythermograph, XBT）获取的温度-深度剖面数据。标准型XBT可获取深度约450米或760米的剖面；若搭载专用仪器，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、日期与时间。数据记录由多组温度-深度值对组成。与温度按均匀5米间隔记录的MBT数据文件不同，XBT数据文件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合格精度所需的最少关键点（“拐点”）。但在数据输出时，用户可选择按拐点输出温度值，或通过插值得到均匀深度间隔下的温度值。