Interface MagneticFieldOptions

Altitude in feet above mean sea level. Defaults to 0 (sea level).

The WMM uses altitude above the WGS-84 ellipsoid (HAE). MSL altitude is an approximation; the difference (geoid undulation) is typically under 100 m and has negligible effect on declination at aviation altitudes.

Date for the computation. Defaults to the current date.

The WMM2025 model is valid from 2025.0 to 2030.0. Outside this range the model accuracy degrades but computations still produce results.

Decimal year for the computation (e.g. 2025.5). Takes priority over date when both are provided.