Temperature profiles from expendable bathythermograph (XBT) casts from the USS R.A. OWENS and other platforms in a world-wide distribution in support of the Integrated Global Ocean Services System (IGOSS) project from 09 August 1968 to 01 August 1974 (NODC Accession 7500699)

XBT data were collected from the R.A. OWENS and other platforms in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the US Navy; Ships of Opportunity and US Navy; Naval Oceanographic Office (NAVOCEANO) from 09 August 1968 to 01 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.

投放式深度温度记录仪（expendable bathythermograph, XBT）数据采集自R.A. OWENS号及其他平台，用于支撑综合全球海洋服务系统（Integrated Global Ocean Services System, IGOSS）项目。该批数据由美国海军、机会观测船（Ships of Opportunity）及美国海军海洋学办公室（Naval Oceanographic Office, NAVOCEANO）于1968年8月9日至1974年8月1日期间采集完成，后由美国国家海洋数据中心（National Oceanographic Data Center, NODC）按照NODC标准的通用深度温度记录仪输出（Universal Bathythermograph Output, UBT）格式进行标准化处理。完整的格式说明文档可通过NODC官网获取，网址为www.nodc.noaa.gov/General/NODC-Archive/bt.html。

UBT文件格式用于记录通过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；配备专用仪器时，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-深度值配对构成。与以均匀5米间隔记录温度值的MBT数据文件不同，XBT数据文件中的温度值对应非均匀深度测点，这些测点为以可接受精度记录温度曲线所需的最少数量的“拐点”。不过在数据输出阶段，用户可选择直接获取拐点处的温度值，或通过插值得到均匀深度间隔下的温度值。