Global Positioning System (GPS)

The Global Positioning System (GPS) has been used for years as a navigational tool and as a geographic mapping aid, and when used well, has revolutionised family holidays, shipping, and logistics, and enabled services like Uber.

When used badly, trucks have gotten stuck on winding country lanes, and unsuspecting drivers have had their cars stranded in fast-moving streams.  However, GPS can also be used for other purposes when integrated with other web technologies such as RSS.

Alt text: Delivery driver using a GPS satnav device to locate a customer’s address.

Image: GPS has revolutionised logistics. Delivery drivers don’t need such detailed local knowledge, making deliveries quicker and more reliable. GPS data can also feed into the company system, so customers can be kept informed when their delivery is nearby through tracking functions on the website or app.

GPS accuracy

Normal GPS signals can suffer from a phenomenon called multipath propagation, where the radio signals from the satellites can bounce off buildings causing the device to give inaccurate readings and incorrect positioning. To alleviate this problem, modern smartphones and high-end sat-navs utilise an A-GPS chip (Assisted GPS) to accurately work out a user’s location by using the mobile network to quickly download GPS satellite positioning information for quicker first-fix location. Some smartphones also utilise mobile cell triangulation and Wi-Fi positioning for accurate locating when not outdoors.

More than sat-nav

The linking of GPS and RSS can be used for Mobile Augmented Reality Systems (MARS), where an overlay of data is positioned on top of an image viewed through a smartphone camera. For example, the Wiktitude world browser uses location and direction information obtained via the GPS and compass in the smartphone and relays RSS overlay data to the image being picked up via the phone’s camera. Layar is another app that uses the GPS co-ordinates to deliver augmented-reality data that allows for a multitude of locational-based information to be shown, such as places of interest, properties for sale, train/tube station locations, and much more.

Some smartphone apps use these techniques to deliver a personalised marketing experience to registered users. For example, German company Coupies have released an app that works out a user’s location and downloads money-off coupons for stores in the vicinity. Mobile operator O2 have launched moments for their customers, which operates in a similar way. Registered users can scan through a selection of offers from partner companies and download coupons to their phone which are valid in their local stores, again derived from GPS, Wi-Fi, and Mobile triangulation.

Another great example of the extension of GPS technology to new apps and ideas is Pokémon GO, which uses augmented reality and took the world by storm on its launch back in 2016. Players explored real-world locations to find the game characters.