{
 "schema": "ausmt-survey-metadata",
 "version": "0.1",
 "survey_id": "roxby-downs-2018",
 "title": "Roxby Downs Regional MT 2017-18",
 "dates": {
  "coverage": {
   "year_start": 2017,
   "year_end": 2018
  }
 },
 "abstract": "Magnetotelluric survey of the Roxby Downs and Olympic Dam region, South Australia, acquired for BHP Billiton by Zonge Engineering and Research Organization between 26 November 2017 and 18 March 2018 (Zonge job 170325, survey envelope 2018SA018) and later released open-file by the Geological Survey of South Australia. Two stages: a broadband stage of roughly 5 km spacing with overnight recordings, and an audio-band stage of roughly 1 km spacing with recordings of two hours or more. Acquisition used Phoenix MTU-5A receivers with MTC-150 induction coils and 100 m electric dipoles, remote-referenced. A 7 degree magnetic declination was applied in processing, so the tensors are referenced to true north. Measured across the 764 files as served: the remote reference is not universal, 751 of the 764 being remote-referenced and 13 single-site solutions. One transfer function, RD18-188e, is served in this package but withheld from the published products: its solution of record sits in the conjugate quadrant and does not pass the sign-convention gate, so 763 of the 764 reach the catalogue.",
 "subjects": [
  {
   "code": "370602",
   "scheme": "ANZSRC-FoR-2020",
   "label": "Electrical and electromagnetic methods in geophysics",
   "uri": "https://linked.data.gov.au/def/anzsrc-for/2020/370602"
  }
 ],
 "contributors": [
  {
   "name": "Zonge Engineering and Research Organization (Australia) Pty Ltd",
   "name_type": "organisation",
   "role": "DataCollector"
  },
  {
   "name": "BHP Billiton",
   "name_type": "organisation",
   "role": "Sponsor"
  },
  {
   "name": "BHP Billiton Olympic Dam Corporation Pty Ltd",
   "name_type": "organisation",
   "role": "RightsHolder"
  },
  {
   "name": "Geological Survey of South Australia",
   "name_type": "organisation",
   "role": "Distributor",
   "ror": "https://ror.org/0121cjp70"
  }
 ],
 "organisations": [
  {
   "name": "Geological Survey of South Australia",
   "ror": "https://ror.org/0121cjp70",
   "roles": [
    "custodian"
   ],
   "primary_custodian": true
  }
 ],
 "rights": {
  "license": "CC-BY-4.0",
  "access": "open"
 },
 "extent": {
  "bbox": {
   "west": 136.634979,
   "south": -30.814717,
   "east": 137.45546,
   "north": -30.327016
  }
 },
 "relationships": [
  {
   "identifier": "https://pid.sarig.sa.gov.au/document/mesac26852",
   "identifier_type": "URL",
   "relation": "IsVariantFormOf"
  }
 ],
 "provenance": {
  "generated": "2026-09-09T06:47:27Z",
  "generator": "ausmt/extract.build_portal 0.2.1"
 }
}