Temperature profiles from expendable bathythermograph (XBT) casts from the NOAA Ship Oregon in the Gulf of Alaska in support of the Integrated Global Ocean Services System (IGOSS) project from 01 May 1975 to 05 May 1975 (NODC Accession 7500479)

XBT data were collected from the NOAA Ship Oregon in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the National Marine Fisheries Service (NMFS) from 01 May 1975 to 05 May 1975. 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.

本数据集的抛弃式深海测温仪（Expendable Bathythermograph，XBT）数据采集自NOAA俄勒冈号科考船，旨在支撑全球海洋综合服务系统（Integrated Global Ocean Services System，IGOSS）项目。数据由美国国家海洋渔业局（National Marine Fisheries Service，NMFS）于1975年5月1日至1975年5月5日期间采集。美国国家海洋数据中心（National Oceanographic Data Center，NODC）将数据处理为符合其标准的通用深海测温仪输出（Universal Bathythermograph Output，UBT）格式。完整格式说明可从NODC官网获取，网址为www.nodc.noaa.gov/General/NODC-Archive/bt.html。
UBT文件格式用于存储通过XBT获取的温深剖面数据。标准XBT可获取约450米或760米水深的温深剖面；搭载特殊仪器时，测量水深可达1830米。每次观测均附带记录航次信息、观测位置、观测日期及时间。数据记录由温深数值对构成。与机械式深海测温仪（Mechanical Bathythermograph，MBT）数据文件不同，后者以5米的均匀间隔记录温度数值，而XBT数据文件中的温度数值对应非均匀水深。这些水深点为满足温度曲线可接受的记录精度所需的最少点数（即“拐点”）。不过在数据输出时，用户可选择获取拐点处的温度数值，或通过插值得到均匀水深间隔下的温度数值。