The global positioning system (GPS) has changed the way we navigate. The technology is found in mobile devices, ATMs, package delivery services, communication networks, forecasting and rescue efforts to name a few. The GPS system is comprised of three segments – 27 satellites maintained by the US Government that use trilateration to pinpoint your location, ground stations that monitor and maintain the satellites, and GPS receivers. There is also a second system of 24 satellites maintained by the Russian Government called GLONASS (GLObal NAvigation Satellite System). Since 2011 GLONASS has had global coverage and many new devices can access that as well as GPS. We take a look at some devices with different specialist applications.
1 Globalsat BU-353s4
Don’t be fooled by the size of this USB receiver – the little device packs a punch when it comes to its GPS. Powered by the SiRF Star IV chipset, it can lock on to satellites in less than 15 seconds, even pinpointing location in dense urban or forested areas – and it’s waterproof too. The magnetic base allows the receiver to be mounted on a car, and it is suitable for tracking fleet vehicles or for marine navigation. It also has a MicroPower mode for conserving substantial energy use.
2 TomTom runner Cardio GPS watch
GPS watches are with those who pound pavement – or even take a dive, as devices such as this one are waterproof up to 50 metres. The internal accelerometer allows you to monitor your runs on a static point such as a treadmill. Although better known for its car systems, TomTom has now entered the world of watches. This device is operated by means of a single button on the wristband instead of the usual touchscreen. It can be connected to a computer to share exercise data.
3 Garmin aera 796
This receiver is built for the skies. With its virtual 3-D technology and on-board terrain database, the aera allows the user to rotate the view of the surrounding land and water with alerts of obstacles. Its internal GPS sends position updates five times a second, and its two serial ports mean it can be connected to hardware. The aera works for both helicopter and fixed-wing aircraft, and the optional City Navigator maps support the addition of street addresses and destinations to the device.
4 Garmin eTrex 20
Garmin is a giant in the portable GPS market and it’s easy to see why with the eTrex. Considered one of the best consumer-grade receivers for its value, the eTrex can be mounted to most vehicles – boats, cars, bicycles, motorcycles – or used as a handheld device. With a battery lasting up to 25 hours, it works with GPS and GLONASS satellites simultaneously, and its microSD card slot allows for a range of map data and charts.
5 Trimble r10 gnss system
A professional system for surveyors with quick but accurate data processing capacity. The receiver allows for data collection with centimetre accuracy even if connection is lost with the device’s network or base station. Surveyors can work outside radio range without needing to move base stations around and it is designed to be compatible with an imaging rover or station positioning sensors for even more flexibility. It incorporates technology to compensate for tilt.
6 Sokkia gcx2
A dual frequency receiver designed for a team working together in the field. When paired with other GCX2 receivers, any one of them can act as a base with up to three additional receivers serving as rovers at a range of up to about 300 metres. It is designed with surveying, construction and geographic information systems in mind. It delivers accurate data at the centimetre level. At 375 grams it is lightweight and can operate in temperatures ranging from -40°C to 85°C.
Originally published by Cosmos as Finding your way with GPS
Megan Toomey is a freelance journalist based in Melbourne.
Read science facts, not fiction...
There’s never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.