Temperature profiles from expendable bathythermograph (XBT) casts from the USCGC MIDGETT in the North Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) project from 26 November 1974 to 17 July 1975 (NODC Accession 7500928)

XBT data were collected from the USCGC MIDGETT in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the US Coast Guard (USCG) from 26 November 1974 to 17 July 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.

投弃式温深计（Expendable Bathythermograph，XBT）数据采集自美国海岸警卫队“米吉特”号（USCGC MIDGETT），用于支撑全球海洋综合服务系统（Integrated Global Ocean Services System，IGOSS）项目。该数据由美国海岸警卫队（United States Coast Guard，USCG）于1974年11月26日至1975年7月17日期间采集完成。数据已由国家海洋数据中心（National Oceanographic Data Center，NODC）处理为NODC标准通用温深计输出（Universal Bathythermograph Output，UBT）格式。完整格式说明可从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XBT仪器获取的温度-深度剖面数据。标准XBT可获取约450米或760米深度的剖面数据；配备专用仪器时，测量深度可达1830米。每次观测均需记录航次信息、观测位置、日期与时间。数据记录由若干温度-深度值对构成。与以5米均匀间隔记录温度值的船载温深计（Moored Bathythermograph，MBT）数据文件不同，XBT数据文件中的温度值对应非均匀深度。这些深度测点为以可接受精度完整记录温度曲线所需的最少点数，即“拐点”。不过在输出时，用户可按需获取拐点处的原始温度值，或通过插值得到等间距深度下的温度值。