IGRF

An implementation of the International Geomagnetic Reference Field, as defined at http://www.ngdc.noaa.gov/IAGA/vmod/igrf.html.

Documentation

data MagneticModel a

Represents a spherical harmonic model of a magnetic field.

Constructors

MagneticModel

Fields

• fieldAtEpoch :: SphericalHarmonicModel a

  Field at model epoch in nT, reference radius in km

• secularVariation :: SphericalHarmonicModel a

  Secular variation in nT / yr, reference radius in km

igrf11 :: Fractional a => MagneticModel a

The International Geomagnetic Reference Field model, 11th edition. Model epoch is January 1st, 2010.

igrf12 :: Fractional a => MagneticModel a

The International Geomagnetic Reference Field model, 12th edition. Model epoch is January 1st, 2015.

igrf13 :: Fractional a => MagneticModel a

The International Geomagnetic Reference Field model, 13th edition. Model epoch is January 1st, 2020.

fieldAtTime

Arguments

:: (Fractional a, Eq a)

=> MagneticModel a

Magnetic field model

-> a

Time since model epoch (year)

-> SphericalHarmonicModel a

Spherical harmonic model of magnetic field at specified time. Field in nT, reference radius in km

Gets a spherical harmonic model of a magnetic field at a specified time offset from the model epoch.

evaluateModelGradientInLocalTangentPlane

Arguments

:: (RealFloat a, Ord a)

=> SphericalHarmonicModel a

Spherical harmonic model

-> a

Spherical radius

-> a

Spherical colatitude (radian)

-> a

Spherical longitude (radian)

-> (a, a, a)

East, North, and up components of gradient

Computes the gradient of the scalar value of the spherical harmonic model at a specified location, in Cartesian coordinates. The result is expressed in a reference frame locally tangent to the sphere at the specified location.