USCGC Healy HLY-02-03 Hourly Position and Weather Data [NCAR/EOL]

This dataset is a composite of several ship underway datasets produced by
the U.S. Coast Guard aboard the USCGC Healy during the Summer SBI Process
Cruise of 2002 (hly-02-03). Routine data logging procedures for underway data
aboard the Healy archive data of different types in physically seperate files.
This has the unfortunate effect of seperating interesting data from the
location of the ship when the measurement was taken. To remedy this situation, a perl script was written by the author to produce
a composite file that contained both ship position and weather information
collected during the above mentioned cruise. This file is a composite of the
PCode-Aft_GGA position datafiles (1 second resolution), the RMYoung-AIR
weather datafiles (3 second resolution), and the TrueWindSpeed datafiles (1
second resolution). The composite is a collection of grab samples (not averages) at approximately
1 hour intervals during the cruise. The composites were constructed by
starting with the time at which the weather observation occurred. The
TrueWindSpeed files were then searched to find corresponding wind information. Lastly, the position files were searched until the position at the observation
time was found. If the times matched or were within 10 seconds of one another,
the weather, winds and position data were written to the composite file. The
position information was converted from Degrees Minutes Seconds format
(DDDMM.SSS) to a Decimal Degrees format (DDD.DDDDD)

本数据集为2002年夏季SBI作业巡航（编号hly-02-03）期间，美国海岸警卫队于希利号海岸警卫队巡逻舰（USCGC Healy）上采集的多份船舶在航数据集的整合版本。希利号上用于在航数据的常规数据日志流程，会将不同类型的存档数据存储于物理独立的文件中，这一机制带来了一处不便：测量时采集的有效数据与船舶位置信息被分离开来。为解决该问题，本文作者编写了Perl脚本，生成了一份整合了上述巡航期间采集的船舶位置与气象信息的复合文件。该复合文件整合了PCode-Aft_GGA位置数据文件（1秒分辨率）、RMYoung-AIR气象数据文件（3秒分辨率）以及TrueWindSpeed风速数据文件（1秒分辨率）。本复合数据集采集了巡航期间约每1小时一次的瞬时采样数据（而非平均值）。复合文件的构建流程以气象观测时刻为起点：首先检索TrueWindSpeed文件以获取对应时段的风速信息，随后检索位置文件直至找到观测时刻对应的船舶位置数据。若时刻完全匹配或时间误差在10秒以内，则将气象、风速及位置数据写入复合文件。位置信息已从度分秒格式（DDDMM.SSS）转换为十进制度格式（DDD.DDDDD）