Temperature profiles from expendable bathythermograph (XBT) casts from the NOAA Ship DISCOVERER in the Gulf of Alaska in support of the Integrated Global Ocean Services System (IGOSS) from 27 July 1977 to 20 November 1977 (NODC Accession 7800211)

XBT data were collected from the NOAA Ship DISCOVERER in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by the US DOC; NOAA; National Ocean Service - Seattle from 27 July 1977 to 20 November 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.

XBT数据系为支撑综合全球海洋服务系统 (Integrated Global Ocean Services System, IGOSS)，由NOAA“发现者号”考察船采集所得。数据由美国商务部 (United States Department of Commerce, US DOC)、NOAA、西雅图国家海洋服务局于1977年7月27日至1977年11月20日期间采集。所有数据已由国家海洋数据中心 (National Oceanographic Data Center, NODC) 处理为NODC标准通用海洋测温仪输出 (Universal Bathythermograph Output, UBT) 格式。完整格式说明可从NODC获取，网址为www.nodc.noaa.gov/General/NODC-Archive/bt.html。
UBT文件格式用于存储通过抛弃式海洋测温仪 (expendable bathythermograph, XBT) 仪器获取的温度-深度剖面数据。标准型XBT可获取深度约450米或760米的剖面数据；搭载特殊型号的XBT则可实现1830米深度的测量。每条观测记录均包含航次信息、观测位置、日期与时间。数据记录由多组温度-深度值对构成。与MBT数据文件不同——MBT数据文件以均匀5米间隔记录温度值——XBT数据文件中的温度值对应非均匀深度，这些深度为以可接受精度记录温度曲线所需的最少“拐点”数量。不过在输出环节，用户可选择按拐点输出温度值，或通过插值得到均匀深度间隔下的温度数据。