Temperature profiles from expendable bathythermograph (XBT) casts from the USCGC CAMPBELL in the North Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) from 26 August 1977 to 08 September 1977 (NODC Accession 7700713)

XBT data were collected from the USCGC CAMPBELL in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by the US Coast Guard from 26 August 1977 to 08 September 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.

本数据集的投弃式温深仪（Expendable Bathythermograph，XBT）数据采集自美国海岸警卫队坎贝尔号巡逻舰（USCGC CAMPBELL），服务于全球海洋综合服务系统（Integrated Global Ocean Services System，IGOSS）。美国海岸警卫队于1977年8月26日至1977年9月8日完成该批次数据的采集。国家海洋数据中心（National Oceanographic Data Center，NODC）将原始数据处理为符合NODC标准的通用温深仪输出（Universal Bathythermograph Output，UBT）格式。完整格式说明可通过NODC官方网站的https://www.nodc.noaa.gov/General/NODC-Archive/bt.html查阅。
UBT文件格式用于存储通过XBT采集得到的温度-深度剖面数据。常规XBT可获取深度约450米或760米的温度剖面；若配备专用仪器，测量深度可达1830米。每份观测记录均包含航次信息、站位坐标、观测日期与时间，数据记录由多组温度-深度值对组成。与以5米为均匀间隔记录温度值的机械温深仪（Mechanical Bathythermograph，MBT）数据文件不同，XBT数据文件的温度值对应非均匀深度。这些非均匀深度测点为以可接受精度记录温度曲线所需的最少数量点，即“拐点”。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间隔下的温度值。