Temperature profiles from expendable bathythermograph (XBT) casts from the USCGC RELIANCE in the East Coast - US/Canada in support of the Integrated Global Ocean Services System (IGOSS) project from 11 August 1976 to 21 August 1976 (NODC Accession 7601541)

XBT data were collected from the USCGC RELIANCE in support of the Integrated Global Ocean Services System (IGOSS) project. Data were collected by the US Coast Guard (USCG) from 11 August 1976 to 21 August 1976. 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（Expendable Bathythermograph, XBT）数据采集自美国海岸警卫队“可靠”号巡逻舰（USCGC RELIANCE），用于支撑全球海洋综合服务系统（Integrated Global Ocean Services System, IGOSS）项目。数据由美国海岸警卫队（United States Coast Guard, USCG）于1976年8月11日至1976年8月21日期间采集完成。数据由美国国家海洋数据中心（National Oceanographic Data Center, NODC）按照其通用温深仪输出（Universal Bathythermograph Output, UBT）标准格式进行规范化处理。完整的格式说明文档可从美国国家海洋数据中心官网的以下链接获取：www.nodc.noaa.gov/General/NODC-Archive/bt.html。
UBT文件格式用于存储通过XBT获取的温度-深度剖面数据。标准型XBT可获取深度约450米或760米的温度剖面。若配备专用改装仪器，最大测量深度可达1830米。每条观测记录均包含航次信息、观测位置、观测日期与精确时间。单条数据记录由一组温度-深度数值对构成。与机械式温深仪（Mechanical Bathythermograph, MBT）数据文件不同——后者以5米为固定间隔记录温度数值，而XBT数据文件中的温度值对应的深度并非均匀分布。XBT的深度采样点选取原则为：以可接受的精度完整记录温度曲线所需的最少数量的“拐点”。但在数据输出环节，用户可自行选择获取拐点处的原始温度值，或通过插值计算得到均匀深度间隔下的温度数值。