IGRF/DGRF Model Parameters and Corrected Geomagnetic Coordinates

Corrected Geomagnetic Coordinates and IGRF/DGRF Model Parameters

This service enables computation of a set of the main geomagnetic field model parameters and transformation from the GEOcentric spherical (geographic) coordinates to the Corrected GeoMagnetic (CGM) coordinates and vice versa. The algorithm is solely based on the DGRF/IGRF geomagnetic field models for Epochs 1900-2025. The B-min approach is applied to calculate CGM coordinates through the near-equator area where the definition of CGM coordinates is invalid. However, GEO <--> CGM transformations are not performed at certain regions where the CGM equator cannot be defined at all.

The following output parameters are calculated:

GEOCENTRIC, CGM, and footprint coordinates of a given point
DGRF/IGRF magnetic field components H (nT), D (deg.), and Z (nT) at this pointand its conjugate point
Geocentric and CGM coordinates of the magnetically conjugate point and the magnetic field line footprint
DGRF/IGRF magnetic field components H (nT), D (deg.), and Z (nT) at footprint point and its conjugate point
Apex of the magnetic field line: the point at a maximum distance
UT at time when given point is at midnight (MLT)
Meridian_angle: the azimuth along a great-circle arc to the North (South) CGM pole measured from the geographic North (South) meridian; positive to East (West)
Oval_angle: the angle between local tangents to the CGM and geographic (geocentric) latitudes;

Brief Description of CGM and Associated MLT Definition

Select input parameters

Year (from 1900 to 2025):
Altitude above the 1-Re surface (km) [from 0. to 40000.]:
Latitude/Longitude below specified in:
Latitude (degrees) [from -90. to -20. or from 20. to 90.]: Longitude (degrees) [from 0. to 360.]:

Profile parameters:
Start Stop Stepsize
Note: Number of points in profile should not exceed 50 (N <=50).

Select output form:
List model data
Create model data file in ASCII format for downloading

Plot model data 
      Note 1: The first selected parameter below always will be along the X-axis, the other selections will be along Y-axis.
              (e.g. if you want a Height profile, you may specify Height as the first parameter in the listing below.)     
      Note 2: User may get a scatter plot if he/she specifies any two parameters below and changes the "connect type"  
              in the "Advanced plot selections" to "show points only"

Select desired output parameters in profile

Input and Model Parameters for Starting Point (SP)

Year

Height, km

Geocentric Latitude, deg.

Geocentric Longitude, deg.

CGM Latitude, deg.

CGM Longitude, deg.

Horizontal comp. H,nT

Declination D,deg.

Vertical comp. Z,nT

Oval angle, deg. (see BD)

Meridian angle, deg. (see BD)

MLT in UT (hours)

Model Parameters for Conjugated Point (CP)

Geocentric Latitude, deg.

Geocentric Longitude, deg.

CGM Latitude, deg.

CGM Longitude, deg.

Horizontal comp. H,nT

Declination D,deg.

Vertical comp. Z,nT

Oval angle, deg. (see BD)

Meridian angle, deg. (see BD)

MLT in UT (hours)

Model Parameters for Footprint Point (FP)

Geocentric Latitude, deg.

Geocentric Longitude, deg.

CGM Latitude, deg.

CGM Longitude, deg.

Horizontal comp. H,nT

Declination D,deg.

Vertical comp. Z,nT

Oval angle, deg. (see BD)

Meridian angle, deg. (see BD)

MLT in UT (hours)

Model Parameters for Conjugated Point
which correspond Footprint Point(CP_FP)

Geocentric Latitude, deg.

Geocentric Longitude, deg.

CGM Latitude, deg.

CGM Longitude, deg.

Horizontal comp. H,nT

Declination D,deg.

Vertical comp. Z,nT

Oval angle, deg. (see BD)

Meridian angle, deg. (see BD)

MLT in UT (hours)

Some other Model Parameters

L-value of Starting Point (Apex), Re

North CGM Pole Latitude for Staring Point
(N_CGM_pole_Latitude_SP), deg.

North CGM Pole Longitude for Staring Point
(N_CGM_pole_Longitude_SP), deg.

South CGM Pole Latitude for Staring Point
(S_CGM_pole_Latitude_SP), deg.

South CGM Pole Longitude for Staring Point
(S_CGM_pole_Longitude_SP), deg.

North CGM Pole Latitude for surface of the Earth
(N_CGM_pole_Latitude_SE), deg.

North CGM Pole Longitude for surface of the Earth
(N_CGM_pole_Longitude_SE), deg.

South CGM Pole Latitude for surface of the Earth
(S_CGM_pole_Latitude_SE), deg.

South CGM Pole Longitude for surface of the Earth
(S_CGM_pole_Longitude_SE), deg.

Advanced plot selections (optional)

Connect Type:	Character size(0.5-2.0)
Plot Symbol:	Symbol Size(0.1-4.0):
Image size (pixels):X: Y:

Find Tsyganenko N modeling HERE
Geomagnetic Field Models, Maps, and Software https://www.ngdc.noaa.gov/geomag/models.shtml

If you have any questions/comments contact:
Dr. Vladimir Papitashvili, c/o Dr. Natalia Papitashvili, E-mail: Natalia.E.Papitashvili@nasa.gov, Space Physics Data Facility, Mail Code 672, NASA/Goddard Space Flight Center, Greenbelt, MD 20771

NASA Official: Dr. Robert Candey, Head of the Space Physics Data Facility