Decodes the GNSS altitude field of an ADS-B airborne position message
(type codes 20-22). Unlike barometric altitude, this field is a plain
12-bit integer in meters - no Gillham or linear-code decoding involved.
Parameters
gnssAltitudeField: number
The raw 12-bit altitude field from bits 8-19 of a GNSS-altitude position ME field.
Decodes the GNSS altitude field of an ADS-B airborne position message (type codes 20-22). Unlike barometric altitude, this field is a plain 12-bit integer in meters - no Gillham or linear-code decoding involved.