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CEAREX Position Data

The CEAREX sample position data include manned station and unmanned buoy drift position data. Also provided on the CEAREX CD-ROM are programs written in C programming language for use on a SUN workstation.

Information in this document has been derived from documentation files on NSIDC's CD-ROM titled Eastern Arctic Ice, Ocean and Atmosphere Data, Volume 1: CEAREX-1, version 1.0, 8/91.


Contents

Data Description
Data Organization and Format
Investigators | References | Acronyms
CD-ROM Documentation File

Data Description:

The CEAREX position data files contain the latitude and longitude of the sample position as well as the time that the position was determined. The data were perused, and any obvious outliers were marked with asterisks.

For the manned camps (POLARBJORN Drift, Oceanography Camp, and Acoustics Camp), hourly listings of position and velocity were derived from a complex demodulation algorithm described in McPhee (1988). The results of complex demodulation for the buoys are not included.

Data Organization:

The position data are contained in 24 ASCII data files, each with one header record followed by "position fix" records with:
  1. time in decimal days of the year
  2. latitude in decimal degrees
  3. longitude in decimal degrees (east positive)

Data Format:

Data files are numbered or named to meet the MS-DOS convention limiting file names to eight characters. Headers for these files contain information about the file contents: original file name, '0' (zero), year, start time (in decimal days of the year), end time (in decimal days of the year), number of fixes, and PI for data collection. The data file headers are not traditional "field" headers. Data records are the same length as the headers.

Manned Station Data

The POLARBJORN Drift Data header is a 65-character record providing information about the start and end times and the source of the data. For example:
	pbdrift 0  1988 start 260.37153 end 335.1278 fixes  4776 PI bunch
	     ERIM satnav fixes = code 0
	     PSC Salargos buoy = code 1
	     ERIM dead reckoning estimates = code 2
	     Scripps ADCP satnav fixes = code 3
The Oceanography Camp Drift header is 62-character record providing information about the start and end times and the source of the data. For example:

	  ocamp 0  1989 start  78.4306 end 120.7347 fixes  753 PI McPhee
	     PSC satnav fixes = code 0
	     PSC Salargos buoy = code 1
	     MFO log from satellite navigator = code 2
The Acoustics Camp Drift header is a 67-character record providing information about the data start and end times, and source. For example:

	 alpha 0  1989 start  82.27431 end 110.43775 fixes  680 PI Baggeroer
	     MIT satnav fixes

Buoy Drift Data

The buoy drift data file headers provide information about file contents, type, file name, year, start date (in decimal days of the year), end date (in decimal days of the year), number of fixes, and data collection PI. All the file names beginning with numbers have the same format, although the record size varies. More detailed information about buoy data format is available in the CD-ROM documentation file.

Investigators:

Arthur Baggeroer, Massachusetts Institute of Technology - A-Camp drift data
Miles McPhee, McPhee Research Company - O-Camp drift data
James Morison, University of Washington - POLARBJORN drift data

For a complete list of all CEAREX investigators, please refer to the CEAREX Investigator Address List.

References:

McPhee, M. G. 1988. Analysis and prediction of short term ice drift. Transactions of the ASME, Journal of Offshore Mechanics and Arctic Engineering 110: 94-100.

Acronyms:

ASCII - American Standard for Computer Information Interchange
ASME - American Society of Mechanical Engineers
CD-ROM - Compact Disc-Read Only Memory
CEAREX - Coordinated Eastern Arctic Experiment
ERIM - Environmental Research Institute of Michigan
NSIDC - National Snow and Ice Data Center
PI - Principal Investigator