This consists of thousands of highly visible trigonometrical beacons , easily accessible town survey marks and benchmarks. TrigNet, the world-class network of permanent continuously operating GNSS base stations distributed throughout South Africa was established in 1998.
Q & A Information Sheet
What is TrigNet?
TrigNet is a network of continuously operating GNSS base stations covering South Africa all managed and controlled by a single control centre situated in the offices of National Geospatial Information (NGI). The first stations in the network were installed in 1999 and by September 2010 consisted of more than 55 operational stations, further stations are planned to expand the network.
The integrated survey system consists of a network of approximately 62 000 control points throughout the country. This survey system is gradually being replaced by more than 50 active GPS base stations to be known as TrigNet which provides post processing and real time GPS correction data.
The integrated survey system is 28 000 white beacons on mountains, hilltops and prominent man-made structures; 24 000 town survey marks of brass stud in a metal box in tarred streets located in 122 cities; and thousands of benchmarks brass studs set in a concrete base originally along railway lines but nowadays alongside roads and highways.