
Garmin has introduced the GHA 15, which uses radar technology to provide height above ground level (AGL) information on G3X Touch flight displays for experimental aircraft and light-sport aircraft (LSA).
The GHA 15 calculates height AGL by sending radio waves to the ground and determining the time it takes to receive the signals back, Garmin officials explain.
GHA 15 processes hundreds of measurements per second and applies digital filters to maintain continuous readings — even over water or in challenging terrain environments, they note.
AGL readouts are shown on the G3X Touch display and drawn on the altitude tape or gauge at altitudes as high as 500 feet AGL.

Using the readings provided by GHA 15, G3X Touch flight displays can also provide AGL audio callouts via their audio output to help keep the pilot’s eyes looking outside the cockpit, company officials said. Beginning at 300 feet, the pilot will hear audible AGL altitude callouts at select intervals down to 1 foot AGL. The pilot can configure the callouts to start and stop at specified altitudes.
Knowing precise height AGL can be helpful to pilots during landings and flying in areas where limited barometric altimeter setting information is available, such as backcountry flying, Garmin officials said
The single module integrates all electronics into a unit that attaches to the bottom of the aircraft. Slightly larger than a deck of cards and weighing less than one pound, the height advisor requires minimal space and modification for installation on the aircraft, company officials said.

The GHA 15 will be available in August 2023 for an expected street price of $1,995.
For more information: Garmin.com