{
 "guid": "",
 "name": "magnetics_wdmam_rtp",
 "licenseInfo": "",
 "tags": [
  "gns. magnetic. anomaly. map. frogtech."
 ],
 "url": "https://gis.gns.cri.nz/server/admin/geophysical/magnetics_wdmam_rtp/ImageServer",
 "title": "MAGNETICS_WDMAM_RTP",
 "thumbnail": "thumbnail/thumbnail.png",
 "summary": "The magnetic grid was generated by FROGTECH from the World Digital Magnetic Anomaly Map (WDMAM) or EMAG3 (2007).  Data sourced from the FROGTECH_NZ_ECS_SEEBASE...",
 "snippet": "The magnetic grid was generated by FROGTECH from the World Digital Magnetic Anomaly Map (WDMAM) or EMAG3 (2007).  Data sourced from the FROGTECH_NZ_ECS_SEEBASE...",
 "culture": "en-US",
 "catalogPath": "",
 "typeKeywords": [
  "Data",
  "Service",
  "Image Service",
  "ArcGIS Server"
 ],
 "spatialReference": "NZGD_2000_New_Zealand_Transverse_Mercator",
 "type": "Image Service",
 "accessInformation": "FROGTECH",
 "description": "Data sourced from the FROGTECH_NZ_ECS_SEEBASE product in the 2013 NZP&M Block Offer Data Pack. The magnetic grid was generated by FROGTECH from the World Digital Magnetic Anomaly Map (WDMAM) or EMAG3 (2007), a global 3-arc-minute resolution grid of the anomaly of the magnetic intensity at an altitude of 5 km above mean sea level. It was compiled from satellite, marine, aeromagnetic and ground magnetic surveys. Information on this dataset can be found in http://www.geomag.us/models/wdmam.html The TMI magnetic data was Reduced to the Pole (RTP). RTP Processing FROGTECH's methodology for RTP processing is determined by the size of the project area. For small surveys, the RTP transformation is simple requiring only one set of geomagnetic parameters. However, for larger surveys, such as the New Zealand SEEBASETM Project, the area is broken down into smaller sub-areas on which the RTP transformation is computed. To obtain Reduction to the Pole (RTP), a transformation from TMI to the magnetic field at the North or South Pole is required. The transformation is computed based on a local geomagnetic inclination and declination. The result of the reduction to the pole (RTP) operation is a field which would be observed if the given field had been observed with vertical polarization, that is, as though observed at one of the Earth\u2019s magnetic poles (refer to the figure on the right). If strong remanent magnetization is present in directions other than that of the Earth, the transformed field will be in error. TMI data is routinely reduced to the pole to shift anomalies directly over their source and for vertical dipping sources to produce symmetric anomalies. The location of sources, particularly source edges, can more readily be determined when the magnetic data has been reduced to the pole. "
}