Wolfram Language & System 10.4 (2016)|Legacy Documentation

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GeomagneticModelData

GeomagneticModelData[]
returns the current magnetic field data for the current location.

GeomagneticModelData[locationspec]
returns the current magnetic field data for a location.

GeomagneticModelData[datespec]
returns the magnetic field data for the specified time for the current location.

GeomagneticModelData[locationspec,datespec]
returns the magnetic field data for the specified time and location.

GeomagneticModelData[locationspec,datespec,component]
returns the component of the magnetic field for the specified time and location.

Details and OptionsDetails and Options

  • GeomagneticModelData[] makes use of $GeoLocation to determine your location and Now to determine current time.
  • The location loc can be specified as latitude and longitude coordinates , coordinates with a height , GeoPosition[], or as a named Entity[]. h can be input as a numeric object in meters or as a Quantity.
  • locationspec can also be a region as specified by a named Entity[], or a listed pair of specific locations or .
  • For regions, results are returned as arrays or an Association of arrays of magnetic field components by default. Arrays are calculated at the height of a specific coordinate point of the grid above the reference datum unless otherwise specified. If that data is not available, it uses a default height of 0 meters.
  • The magnetic field is calculated for the current time using the World Magnetic Model or . The model is updated regularly to account for slow changes in the Earth's magnetic field. Historical magnetic fields use if the date is within their range of validity. Otherwise, GeomagneticModelData uses the International Geomagnetic Reference Field () or, for pre-1900 dates, the model.
  • datespec can be specified by DateObject or DateList.
  • Location and date can also be specified together as Association["Location"->locationspec,"Date"datespec].
  • Components include , , , , , , and . Components are measured relative to the reference ellipsoid .
  • is measured relative to the perpendicular to the reference ellipsoid where positive values are downward. is the field parallel to the surface at that point. is the angle between the north and east components. is the angle between the horizontal component and the vertical component. is the total magnitude of the field. is the magnetic potential.
  • Components and are returned in nanoteslas. and are returned in angular degrees. is returned as nanovolt seconds per meter.
  • All magnetic field components are returned as an Association unless a specific component is requested.
  • GeomagneticModelData[component] returns the component for the current magnetic field at your location.
  • GeomagneticModelData[locationspec,component] returns the component for the current magnetic field at the specified location.
  • GeomagneticModelData[locationspec,component,func] and GeomagneticModelData[locationspec,datespec,component,func] are used to specify the format of output when extended locations are specified.
  • Possible settings for func include:
  • Allreturn all values for extended locations
    Intervalreturn intervals for extended locations
    Maxreturn maximum values for extended locations
    Meanreturn mean value for extended locations
    Minreturn minumum values for extended locations
    StandardDeviationreturn standard deviation for extended locations
  • GeomagneticModelData also includes the following properties: , , , , , and . These can be used to find the respective poles for the current or historical times.
  • GeomagneticModelData takes the following options:
  • GeoZoomLevelAutomaticlevel of resolution of the magnetic field array
    MethodAutomaticmethod for calculating magnetic field
  • Method has the suboption , which allows you to specify what model to use. Available models include , , and .

ExamplesExamplesopen allclose all

Basic Examples  (2)Basic Examples  (2)

Find the magnetic field components at a geographic position:

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Use Entity to specify a location:

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Find the magnetic field at a location and time:

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Introduced in 2015
(10.1)