Temperature profiles from expendable bathythermograph (XBT) casts from the USCGC GALLATIN in the North Atlantic Ocean in support of the Integrated Global Ocean Services System (IGOSS) from 20 October 1972 to 25 November 1972 (NODC Accession 7300508)

XBT data were collected from the USCGC GALLATIN in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by the US Coast Guard from 20 October 1972 to 25 November 1972. 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.

本数据集的抛弃式温深仪（Expendable Bathythermograph, XBT）数据采集自美国海岸警卫队加兰蒂号巡逻舰（USCGC GALLATIN），用于支撑全球海洋综合服务系统（Integrated Global Ocean Services System, IGOSS）的相关工作。该数据由美国海岸警卫队于1972年10月20日至1972年11月25日期间采集完成，后由国家海洋数据中心（National Oceanographic Data Center, NODC）处理为符合其标准的通用温深仪输出格式（Universal Bathythermograph Output, UBT）。完整格式说明可通过NODC官网的https://www.nodc.noaa.gov/General/NODC-Archive/bt.html查询获取。

UBT文件格式用于存储通过抛弃式温深仪（XBT）获取的温深剖面数据。标准型XBT可获取深度约450米或760米的温深剖面，若配备特制仪器，最大测量深度可达1830米。每份观测记录均包含航次信息、观测站位坐标、观测日期与时间，数据记录由多组温深数值对构成。与以5米等间隔记录温度值的机械温深仪（Mechanical Bathythermograph, MBT）数据文件不同，XBT数据文件中的温度值对应非均匀深度——这些深度点选取为以可接受精度完整记录温度曲线所需的最少数量点，即“拐点”。但在数据输出环节，用户可选择获取拐点处的原始温度值，或通过插值得到等深度间隔下的温度数值。