5.2. Geomagnetic Components (or Elements)

Geomagnetic data can be described in a number of different orientations. Component codes are used to describe the individual elements of the geomagnetic vector.

  • X = H*cos(D)

  • Y = H*sin(D)

  • Z = F*sin(I)

  • H = F*cos(I)

  • H = SQRT(X^2 + Y^2)

  • F = SQRT(X^2 + Y^2 + Z^2)

  • tan(D) = Y/X

  • tan(I) = Z/H

Geomagnetic components

Fig. 5.1 Geomagnetic components

Code

Description

X

North Component. The strength of the magnetic field vector in the geographic north direction (northerly values are positive).

Y

East component. The strength of the magnetic field vector in the geographic east direction (easterly values are positive).

Z

Vertical intensity. The strength of the magnetic field vector in the vertical direction (Z is positive down and hence negative south of the geomagnetic equator).

H

Horizontal intensity. The strength of the magnetic field vector in the horizontal plane along the magnetic meridian.

D

Declination or variation. The angle between the magnetic vector and true north (positive east).

I

Inclination. The angle between the magnetic vector and the horizontal plane, in degrees of arc (positive below the horizontal).

F

Total field intensity. The geomagnetic field strength, calculated from and consistent with XYZ or HDZ field elements.