International Geomagnetic Reference Field - Garmin G500H Pilot's Manual

1.3

International Geomagnetic Reference Field

The IGRF (International Geomagnetic Reference Field) model is contained
in the GRS 77 and is only updated once every five years. The IGRF model is
part of the Navigation Database. At system power-up, the IGRF models in the
GRS 77 and in the Navigation Database are compared, and if the IGRF model
in the GRS 77 is out of date, the user is prompted to update the IGRF model in
the GRS 77. The following prompt will appear after the G500H splash screen is
acknowledged on the MFD.
GRS MV DB UPDATE AVAILABLE. UPDATE FROM yyyy TO yyyy
(e.g. 2005 to 2010)
Follow the on-screen instructions.
1) When the Update message appears, to start the update process press the ENT
key with "OK" highlighted. To update at another time, turn the Large knob to
highlight "Cancel" and then press ENT.
2) After the update is complete, press the ENT key to continue normal operation.
190-01150-02 Rev. J
Figure 1-13 GRS MV DB Update
Garmin G500H Pilot's Guide
1-13