Temperature profiles from expendable bathythermograph (XBT) casts from the BARTLETT in the North Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) from 21 September 1977 to 05 October 1977 (NODC Accession 7800095)

XBT data were collected from the BARTLETT in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by the US Navy; Naval Oceanographic Office (NAVOCEANO) from 21 September 1977 to 05 October 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.

本投弃式温深仪（Expendable Bathythermograph, XBT）数据采集自巴特利特号（BARTLETT），用于支撑全球海洋综合服务系统（Integrated Global Ocean Services System, IGOSS）。数据由美国海军下属海军海洋局（Naval Oceanographic Office, NAVOCEANO）于1977年9月21日至1977年10月5日采集完成。数据经美国国家海洋数据中心（National Oceanographic Data Center, NODC）处理，符合其通用温深仪输出（Universal Bathythermograph Output, UBT）标准格式。完整格式说明可通过NODC官方网站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。标准型XBT可获取最大深度约450米或760米的剖面数据；若配备专用仪器，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、观测日期与时间。数据记录由温度-深度值对组成。与机械式温深仪（Mechanical Bathythermograph, MBT）数据文件采用均匀5米间隔记录温度值不同，XBT数据文件的温度值对应非均匀深度间隔，仅在将温度曲线记录至可接受精度所需的最少采样点（即拐点）处采集数据。不过在数据输出时，用户可选择获取拐点处的原始温度值，或通过插值得到均匀深度增量对应的温度值。