Temperature profiles from expendable bathythermograph (XBT) casts from the USNS SILAS BENT in the North Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 12 January 1974 to 03 May 1974 (NODC Accession 7400404)

XBT data were collected from the USNS SILAS BENT in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the US Navy; Naval Oceanographic Office (NAVOCEANO) from 12 January 1974 to 03 May 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.

投弃式温深计（expendable Bathythermograph，XBT）数据采集自美国海军舰只西拉斯·本特号（USNS SILAS BENT），用于支撑全球海洋综合服务系统（Integrated Global Ocean Services System，IGOSS）项目。该数据由美国海军海洋局（Naval Oceanographic Office，NAVOCEANO）于1974年1月12日至1974年5月3日期间采集，由国家海洋数据中心（National Oceanographic Data Center，NODC）处理为符合NODC标准的通用温深计输出格式（Universal Bathythermograph Output，UBT）。完整的格式说明可从国家海洋数据中心（NODC）的官网www.nodc.noaa.gov/General/NODC-Archive/bt.html获取。

UBT文件格式用于采集自投弃式温深计（expendable Bathythermograph，XBT）的温度-深度剖面数据。标准投弃式温深计可获取约450米或760米深度的剖面数据；配备专用仪器时，测量深度可达1830米。每条观测记录均包含航次信息、观测位置、日期与时间。数据记录由温度-深度值对组成。与机械式温深计（Mechanical Bathythermograph，MBT）数据文件不同——其温度值以均匀的5米间隔记录——XBT数据文件中的温度值对应非均匀深度。这些深度点为记录温度曲线至可接受精度所需的最少测点（即“拐点”）。在数据输出时，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间隔下的温度值。