Temperature profiles from expendable bathythermograph (XBT) casts from the BARTLETT in the North Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) from 09 October 1977 to 25 October 1977 (NODC Accession 7800226)

XBT data were collected from the BARTLETT in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by the US Navy; Naval Oceanographic Office (NAVOCEANO) from 09 October 1977 to 25 October 1977. 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.

抛弃式温深计（Expendable Bathythermograph，XBT）数据采集自"巴特利特"号调查船，用于支撑全球海洋综合服务系统（Integrated Global Ocean Services System，IGOSS）的运行。该数据由美国海军及其海军海洋学办公室（Naval Oceanographic Office，NAVOCEANO）于1977年10月9日至1977年10月25日采集完成，后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（Universal Bathythermograph Output，UBT）格式。完整格式说明可从国家海洋数据中心官网www.nodc.noaa.gov/General/NODC-Archive/bt.html获取。

UBT文件格式用于存储通过抛弃式温深计获取的温度-深度剖面数据。标准型XBT可获取约450米或760米深度的剖面数据；若配备专用仪器，测量深度可达1830米。每条观测记录均包含航次信息、站位坐标、观测日期与时间，数据记录由温度-深度值对组成。
与机械温深计（Mechanical Bathythermograph，MBT）数据文件不同——后者以固定5米间隔记录温度值，XBT数据文件的温度值对应非均匀深度。这些深度点为以可接受精度记录温度曲线所需的最少点数（即"拐点"）。但在数据输出时，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。