GPS: What Is It and How Does it Work in Surveying?
History of GPS
Satellite navigation, or satnav, is a system that uses satellites and small electric receivers based on Earth to determine the receiver’s location. These days, there are a handful of global navigation satellite systems, run by the USA, the European Union and Russia.
The name you’re probably most familiar with is America’s Global Positioning System (GPS). It was first developed by the US Navy in the 1960s to improve how ships navigated the oceans when five satellites orbited Earth allowing ships to fix their position once an hour. Today we can use satellite navigation to pinpoint the location of our phones, for directions in car-based satnavs and when using industrial equipment. The technology is now so advanced that GPS can determine a receiver’s location to just a few metres almost immediately – as anyone who’s turned to Google Maps when they’re lost can tell you!
Using GPS in Surveying
GPS is a brilliant addition to the surveying industry because it provides precise, accurate mapping far faster than conventional methods. What used to take a large team of surveyors several weeks can now take one or two surveys just a few hours, massively improving productivity.
Additionally, satellite navigation is not limited by ‘lines of sight’ visibility in the same way other survey stations are, as stations can be placed anywhere with a view of the sky and at great distances from one another. This is also useful for surveying waterways where there are fewer points of reference on land.
You can learn even more about GPS and its uses on the Ordnance Survey website!
The ‘constellation’ of satellites orbiting Earth, from gps.gov