Temperature profiles from expendable bathythermograph (XBT) casts from the USNS KANE and USNS WILKES in the North/South Atlantic Ocean and Indian Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 12 April 1977 to 31 May 1977 (NODC Accession 7700604)

XBT data were collected from the USNS KANE and USNS WILKES in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the US Navy; Naval Oceanographic Office (NAVOCEANO) from 12 April 1977 to 31 May 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.

投弃式温深仪（XBT）数据采集自美国海军舰艇USNS KANE与USNS WILKES，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军海洋局（NAVOCEANO）于1977年4月12日至1977年5月31日采集，并由美国国家海洋数据中心（NODC）处理为符合NODC标准的通用温深仪输出（Universal Bathythermograph Output, UBT）格式。完整的格式说明可通过NODC官网www.nodc.noaa.gov/General/NODC-Archive/bt.html获取。

UBT文件格式用于存储通过投弃式温深仪（XBT）获取的温度-深度剖面数据。标准XBT可获取约450米或760米水深范围内的剖面数据；搭载专用仪器时，测量水深可达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。与机械温深仪（Mechanical Bathythermograph, MBT）数据文件采用5米等间隔记录温度值的方式不同，XBT数据文件中的温度值对应非均匀分布的水深。这些水深点为以可接受的精度记录温度曲线所需的最少采样点（即“拐点”）。在数据输出环节，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。