Temperature profiles from expendable bathythermograph (XBT) casts from the NOAA Ship MT MITCHELL in the Gulf of Mexico and North Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 24 April 1978 to 30 April 1978 (NODC Accession 7800375)

XBT data were collected from the NOAA Ship MT MITCHELL in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the National Ocean Service (NOS) from 24 April 1978 to 30 April 1978. 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.

抛投式温深仪（Expendable Bathythermograph，XBT）数据由美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration，NOAA）的MT MITCHELL号科考船采集，用于支持综合全球海洋服务系统（Integrated Global Ocean Services System，IGOSS）项目。该数据由美国国家海洋服务局（National Ocean Service，NOS）于1978年4月24日至1978年4月30日期间采集完成。数据经美国国家海洋数据中心（National Oceanographic Data Center，NODC）处理，转换为NODC标准通用温深仪输出（Universal Bathythermograph Output，UBT）格式。完整的格式说明可通过NODC官方网站www.nodc.noaa.gov/General/NODC-Archive/bt.html获取。
UBT文件格式用于存储通过抛投式温深仪（Expendable Bathythermograph，XBT）获取的温度-深度剖面数据。标准型XBT可获取约450米或760米深度的温度剖面；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-深度值对组成。与机械温深仪（Mechanical Bathythermograph，MBT）数据文件不同——后者的温度值以均匀5米间隔进行记录——XBT数据文件中的温度值对应非均匀深度。这些深度点为以可接受精度完整记录温度曲线所需的最少关键点（亦称“拐点”）。但在数据输出时，用户可选择获取拐点处的原始温度值，或通过插值运算得到均匀深度增量下的温度值。