AusMT survey data — licence and attribution
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Licence:     CC-BY-4.0
Licence URL: https://creativecommons.org/licenses/by/4.0/
Licensor:    Adelaide University
Year:        2009

Attribution (cite as):
  Adelaide University (2009) Curnamona Gawler Link MT Transect 2009 (Adelaide University)

This LICENSE.txt travels with the data files in this archive. The transfer functions were
distributed via the AusMT portal, which serves only openly licensed Australian magnetotelluric
releases; the licence above is the custodian's, set in the survey's survey.yaml. Reuse under the
terms of that licence (https://creativecommons.org/licenses/by/4.0/).

Changes were made: Fifteen of the thirty served files, the broadband half, are byte identical to the collection files. The other fifteen, the long period half, carry a header date repair and nothing else: their delivered ACQDATE reads "Sep 2009" and their delivered FILEDATE reads "Nov 2009", a month and a year with no day, which mt_metadata answers with 2009-09-01 and 2009-11-01. The answer it gives for ACQDATE is 23 to 25 days before the station it describes was deployed and precedes the first day of the survey, so every long period station would publish a start date the survey cannot have had. ACQDATE is therefore set to the station start the owner's field sheet gives for that station, 2009-09-24 to 2009-09-26, and FILEDATE to 2009-11-01. The FILEDATE rewrite changes no published value: 2009-11-01 is what the reader already derives from the delivered "Nov 2009", and it is written only because the tool cannot normalise one date field and leave a value in the other that no reader takes one way. The day of that month is not a source fact and no source read states it. No other byte of any file is changed: no data block, no other header line, no padding and no line ending, proved file by file against provenance/as-delivered/. Each repaired file carries nine lines after its >INFO line naming the source file, its path in the collection, its sha256, the kept copy, the defect, the change, the basis, the ruling and the tool. The fifteen broadband files are NOT repaired: their ACQDATE values all carry a day of 22 or above and their FILEDATE values a day of 26, so no value of either field can be read month first, and mt_metadata's reading equals the day first reading at 15 of 15.. AusMT serves derived renditions (canonical EMTF XML; MTH5 where available) generated from the deposited files; per-station conditioning notes are recorded in the machine-readable products.
