Documentation Center

  • Trial Software
  • Product Updates

igrf11magm

Calculate Earth's magnetic field using 11th generation of International Geomagnetic Reference Field

Syntax

[mag_field_vector, hor_intensity, declination, inclination, total_intensity, mag_field_sec_variation, sec_variation_horizontal, sec_variation_declination, sec_variation_inclination, sec_variation_total] = igrf11magm(height, latitude, longitude, decimal_year)

Description

[mag_field_vector, hor_intensity, declination, inclination, total_intensity, mag_field_sec_variation, sec_variation_horizontal, sec_variation_declination, sec_variation_inclination, sec_variation_total] = igrf11magm(height, latitude, longitude, decimal_year) calculates the Earth's magnetic field and the secular variation at a specific location and time. This function uses the 11th generation of the International Geomagnetic Reference Field (IGRF-11).

Input Arguments

height

Scalar distance, in meters, from the surface of the Earth.

latitude

Scalar geodetic latitude, in degrees. North latitude is positive, south latitude is negative.

longitude

Scalar geodetic longitude, in degrees. East longitude is positive, west longitude is negative.

decimal_year

Scalar year, in decimal format. This value is the desired year to include any fraction of the year that has already passed.

Output Arguments

mag_field_vector

Magnetic field vector, in nanotesla (nT). Z is the vertical component (+ve down).

hor_intensity

Horizontal intensity, in nanotesla (nT).

declination

Declination, in degrees (+ve east).

inclination

Inclination, in degrees (+ve down).

total_intensity

Total intensity, in nanotesla (nT).

mag_field_sec_variation

Secular variation in magnetic field vector, in nT/year. Z is the vertical component (+ve down).

sec_variation_horizontal

Secular variation in horizontal intensity, in nT/year.

sec_variation_declination

Secular variation in declination, in minutes/year (+ve east).

sec_variation_inclination

Secular variation in inclination, in minutes/year (+ve down).

sec_variation_total

Secular variation in total intensity, in nT/year.

Examples

Calculate the magnetic model 1000 meters over Natick, Massachusetts on July 4, 2005 using IGRF-11:

[XYZ, H, DEC, DIP, F] = igrf11magm(1000, 42.283, -71.35, ...
decyear(2005,7,4))

XYZ =

  1.0e+004 *

    1.8982   -0.5176    4.9558

H =

  1.9675e+004

DEC =

  -15.2524

DIP =

   68.3467

F =

  5.3320e+004

More About

expand all

Tips

  • The igrf11magm function is valid between the heights of –1000 meters to 600000 meters.

  • The igrf11magm function is valid between the years of 1900 and 2015.

  • This function has the limitations of the International Geomagnetic Reference Field (IGRF).

References

Lowes, F. J. "The International Geomagnetic Reference Field: A 'Health' Warning." January, 2010. http://www.ngdc.noaa.gov/IAGA/vmod/igrfhw.html

Blakely, R. J. Potential Theory in Gravity & Magnetic Applications, Cambridge, UK: Cambridge University Press, 1996.

Was this topic helpful?