Temperature profiles from expendable bathythermograph (XBT) casts from the NOAA Ship FAIRWEATHER in the North Pacific Ocean in support of the Integrated Global Ocean Services System (IGOSS) from 14 April 1975 to 17 April 1975 (NODC Accession 7500261)

XBT data were collected from the NOAA Ship FAIRWEATHER in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by the US DOC; NOAA; National Ocean Service - Seattle from 14 April 1975 to 17 April 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.

本数据集的抛弃式温深计（Expendable Bathythermograph，XBT）数据采集自美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration，NOAA）“费尔韦瑟号”科考船，采集工作服务于全球海洋综合服务系统（Integrated Global Ocean Services System，IGOSS）。数据由美国商务部（United States Department of Commerce，US DOC）、美国国家海洋和大气管理局（NOAA）及西雅图国家海洋服务局于1975年4月14日至1975年4月17日期间采集。数据由国家海洋数据中心（National Oceanographic Data Center，NODC）处理为符合NODC标准的抛弃式温深计通用输出格式（Universal Bathythermograph Output，UBT）。完整的格式说明可通过国家海洋数据中心官网的https://www.nodc.noaa.gov/General/NODC-Archive/bt.html获取。

UBT文件格式用于存储通过抛弃式温深计（XBT）采集的温度-深度剖面数据。标准型XBT可获取约450米或760米水深范围内的剖面数据；搭载特制仪器时，测量水深可达1830米。每条观测记录均包含航次信息、观测位置、日期及时间。数据记录由多组温度-深度数值对构成。与机械温深计（Mechanical Bathythermograph，MBT）数据文件不同——后者以固定5米间隔记录温度数值，本XBT数据文件中的温度数值对应非均匀水深。这些水深测点为记录温度曲线至可接受精度所需的最少测点（即拐点）。但在数据输出时，用户可选择获取拐点处的原始温度数值，或通过插值得到均匀水深间隔下的温度数值。