WMMHR-2025¶

World Magnetic Model High Resolution (2025 edition). Computes Earth's magnetic field using spherical harmonic coefficients to degree 133, providing high spatial resolution including crustal field contributions. Valid from approximately 2025 to 2030.

Note

For usage guidance and examples, see Magnetic Field Models in the Learn section.

Geodetic ENZ Output¶

wmmhr_geodetic_enz `builtin` ¶

wmmhr_geodetic_enz(epc: Epoch, x_geod: ndarray, angle_format: AngleFormat, nmax: int = None) -> ndarray

Compute WMMHR-2025 magnetic field in the geodetic ENZ frame.

The geodetic ENZ frame has zenith perpendicular to the WGS84 ellipsoid surface.

Parameters:

Name	Type	Description	Default
`epc`	`Epoch`	Epoch of computation	required
`x_geod`	`ndarray`	Geodetic position [longitude, latitude, altitude_m]. Angle units controlled by angle_format. Altitude always in meters.	required
`angle_format`	`AngleFormat`	Whether longitude/latitude are in degrees or radians	required
`nmax`	`int`	Maximum spherical harmonic degree (1-133). Default: 133 (full resolution).	`None`

Returns:

Type	Description
`ndarray`	numpy.ndarray: Magnetic field [B_east, B_north, B_zenith] in nT

Example

import brahe as bh
import numpy as np

epc = bh.Epoch.from_date(2025, 1, 1, bh.TimeSystem.UTC)
x_geod = np.array([0.0, 80.0, 0.0])
b = bh.wmmhr_geodetic_enz(epc, x_geod, bh.AngleFormat.DEGREES)
print(f"B_east={b[0]:.1f}, B_north={b[1]:.1f}, B_zenith={b[2]:.1f} nT")

Geocentric ENZ Output¶

wmmhr_geocentric_enz `builtin` ¶

wmmhr_geocentric_enz(epc: Epoch, x_geod: ndarray, angle_format: AngleFormat, nmax: int = None) -> ndarray

Compute WMMHR-2025 magnetic field in the geocentric ENZ frame.

The geocentric ENZ frame has zenith along the geocentric radial direction.

Parameters:

Name	Type	Description	Default
`epc`	`Epoch`	Epoch of computation	required
`x_geod`	`ndarray`	Geodetic position [longitude, latitude, altitude_m]. Angle units controlled by angle_format. Altitude always in meters.	required
`angle_format`	`AngleFormat`	Whether longitude/latitude are in degrees or radians	required
`nmax`	`int`	Maximum spherical harmonic degree (1-133). Default: 133 (full resolution).	`None`

Returns:

Type	Description
`ndarray`	numpy.ndarray: Magnetic field [B_east, B_north, B_zenith] in nT

Example

import brahe as bh
import numpy as np

epc = bh.Epoch.from_date(2025, 1, 1, bh.TimeSystem.UTC)
x_geod = np.array([0.0, 80.0, 0.0])
b = bh.wmmhr_geocentric_enz(epc, x_geod, bh.AngleFormat.DEGREES)

ECEF Output¶

wmmhr_ecef `builtin` ¶

wmmhr_ecef(epc: Epoch, x_geod: ndarray, angle_format: AngleFormat, nmax: int = None) -> ndarray

Compute WMMHR-2025 magnetic field in the ECEF frame.

Parameters:

Name	Type	Description	Default
`epc`	`Epoch`	Epoch of computation	required
`x_geod`	`ndarray`	Geodetic position [longitude, latitude, altitude_m]. Angle units controlled by angle_format. Altitude always in meters.	required
`angle_format`	`AngleFormat`	Whether longitude/latitude are in degrees or radians	required
`nmax`	`int`	Maximum spherical harmonic degree (1-133). Default: 133 (full resolution).	`None`

Returns:

Type	Description
`ndarray`	numpy.ndarray: Magnetic field [B_x, B_y, B_z] in ECEF frame, in nT

Example

import brahe as bh
import numpy as np

epc = bh.Epoch.from_date(2025, 1, 1, bh.TimeSystem.UTC)
x_geod = np.array([0.0, 80.0, 0.0])
b = bh.wmmhr_ecef(epc, x_geod, bh.AngleFormat.DEGREES)

WMMHR-2025¶

Geodetic ENZ Output¶

wmmhr_geodetic_enz builtin ¶

Geocentric ENZ Output¶

wmmhr_geocentric_enz builtin ¶

ECEF Output¶

wmmhr_ecef builtin ¶

See Also¶

wmmhr_geodetic_enz `builtin` ¶

wmmhr_geocentric_enz `builtin` ¶

wmmhr_ecef `builtin` ¶