In 2015, Inigo San Gil moved these data to the Drupal Ecological Information Management System, thus modernizing a bit the way data is managed and distributed.
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Data for the original stake locations was submitted by Andrew G. Fountain to the data manager in August, 1997. The column showing "file name" identifies the original file containing that record. These are ascii text files and can be found in the McMurdo LTER data manager's home directory on INSTAAR's Unix system.
Once submitted to INSTAAR, the data manager used Microsoft Excel and Access software to produce files that were in more of a relational mode. The resulting files are represented in the "glstkloc.dat" file (ascii text, comma delimited format), and "glstkloc.txt" file (MS-DOS text format).
Initially, there was no date associated with each record in the data file. However, due to constant movement of ice on glaciers, the stake locations required subsequent measurements during the 1996-97 field season. When this occurred, a field for date was added to this file. Dates from the initial GPS measurements were acquired from the raw data files submitted by Andrew Fountain. If uncertain about what date to use, confirmation was made with Karen Lewis.
Upon verifying altitude corrections for the gps locations with Bjorn Johns of UNAVCO (in March, 1998), Karen Lewis discovered that all of the ellipsoidal heights to sea level obtained by precise GPS measurements were too short by 55.24 meters. Denise Steigerwald therefore adjusted the elevations for these stakes by adding 55.24 meters.
In April, 2000, Denise Steigerwald added fields for dataset code and glstkid. Dataset code would allow the data to be linked to the metadata in a relational database. Glstkid is a code that ties stake records to points on a GIS base map being developed by Michael Prentice at the University of New Hampshire. In addition, Denise:
- Removed records associated with "B" (replacement) stakes. Coordinates for these stakes match those provided for the original stakes. Data sets containing replacement stake records had their stake values divided into 'stake' and 'stk replcmnt' fields, thus allowing the 'stake' fields to be linked between the locations file and the data files.
- Converted all latitudes and longitudes from degrees-minutes-seconds to degrees in decimal format. This would allow them to be stored in numeric format rather than as text.