Ahrs Operation - Garmin G3X Pilot's Manual

System Overview

AHRS OPERATION

The Attitude and Heading Reference System (AHRS) performs attitude, heading, and
vertical acceleration calculations for the G3X System, utilizing GPS, magnetometer,
and air data in addition to information from its internal sensors. Attitude and heading
information are updated on the PFD while the AHRS receives appropriate combinations
of information from the external sensor inputs.
The AHRS (GSU 73) corrects for shifts and variations in the Earth's magnetic field by
applying the Magnetic Field Variation Database. The Magnetic Field Variation Database
is derived from the International Geomagnetic Reference Field (IGRF). The IGRF is a
mathematical model that describes the Earth's main magnetic field and its annual rate
of change. The database is updated approximately every 5 years. Failure to update this
database could lead to erroneous heading information being displayed to the pilot.
Magnetometer Data
AHRS no-
AHRS Normal
Mag Mode
Operation
18
GPS Data
Air Data
AHRS no-Mag/
no-Air Mode
Heading Invalid
Garmin G3X Pilot's Guide
Magnetometer Data
Air Data
AHRS
no-GPS
Attitude/Heading Invalid
Mode
190-01115-00 Rev. G