Australian Height Datum. Australian Height Datum (AHD) is the datum (adopted by the National Mapping Council of Australia) to which all vertical control for mapping is to be referred.
Australian Height Datum. Level datum measured in metres.
Australian Height Datum. Established in 1971 as a national level datum based on the average mean sea level around the Australian coast line. Determined by a national levelling survey and continuous tide gauge readings over a period of 3 years at 30 locations.