Etosha National Park has a long history of aerial game counts, the first experimental counts being conducted in the late 1960's. Only in the late 1980's were systematic sample counts introduced. A big advance in the actual procedure and analysis was made with the introduction of GPS and GIS software used since 1995. The 2000 census is the third census flown based on GPS transects and were GPS waypoints were recorded for sightings made.