GPS – A Primer for travelers

GPS or Global Positioning System is a means for finding the accurate position of a person/device through a receiver anywhere on the Earth. GPS provides a Latitude/Longitude for position that can be used in a wide variety of applications from Navigation to getting Yellow Page Information in a neighborhood.

GPS is owned and operated by the US Military and was opened in the 80’s for civilian commercial use and is free of cost to use for anyone who has a GPS receiver.

GPS constellation

It consists of an orbital constellation of a minimum of 24 MEO (Medium Earth Orbit) Satellites that keep orbiting the Earth. As long as a user is not inside covered buildings or under thick forest cover, they should be able to detect at least 3-4 GPS satellites, enabling the receiver to calculate it’s current position. Basically, signals are sent to the GPS receivers that are visible to the user. The receiver calculates the time taken to reach the GPS satellite and back and uses a trilateration method to arrive at a lat/long position. There are methods to increase the accuracy of the GPS (pinpoint accuracy) using AGPS (Assisted GPS).

GPS is used in a wide variety of environments – Route Guidance for cars, Marking hiking trails for hikers, for measuring distance travelled by runners, for mapping areas by surveyors, for tracking fleets by Corporates etc..  GPS receivers used to be the size of a hockey puck in the early 90s. Today they are small enough to be integrated into mobile phones and handheld devices.

Can I get GPS in India too?

GPS is available as a service globally and will work as long as a user has a GPS receiver (which can be in navigation systems, mobile phones etc..). For travelers, GPS devices used in navigation applications offer 2 key functionalities:

  • Basic Route Guidance will utilize Digital Maps to provide Directions from Point A to Point B highlighted on a Map. The route will be highlighted on a Map between Origin and Destination and a location icon may trace the map as the traveler is traveling on the road. Earlier systems provided these “Dot on the Map” systems without turn by turn instructions.
  • True Route Guidance with Turn by Turn instructions. This technique would use dynamic positioning to keep verifying a person or vehicle’s current location and will provide the user with Turn by turn instructions to a destination as the person is traveling.  Another view provided could include the route not only  be highlighted on a Map, but a location icon will trace a path on the Map as one moves on the road along with turn by turn instructions. Other information such as overall distance, countdown distance to destination, visual and aural clues and a list of directions to get to a destination may also be provided.

GPS devices also offer a variety of other information such as how far one has travelled, current speed and average speed, estimated time of arrival to a destination etc.. In addition, Navigation systems are tied to Yellow Page information and Points of interest making it easier for people to get to key locations easily.

A key ingredient to making navigation work in an area is the availability of digital Maps in order to overlay the Positioning information on devices. Thanks to companies like Map My India and SatNav, India now has fairly robust coverage of digital maps for use in Navigation systems. GPS when overlaid on Maps can be used for showing Routes from Point A to B and in more advanced systems can be used for Turn by Turn Guidance. Indian Maps are now a lot more accurate than people think, thanks to companies such as Map My India and SatNav who do periodical updates to the Digital Maps.

How does this benefit travelers in India?

Vx140_MapmyIndiaTravelers can now use their own Mobile Phones (with GPS) or have the choice of  dedicated Navigation Systems that can be used in cars. A dedicated Navigation system in a car is easier to use and comes with other functionalities such as multiplying as a hands free system by serving as a Bluetooth Speaker & entertainment device in a car. Navigation systems also come with mounting equipment and car chargers to allow for long distance trips. Full fledged Navigation Systems for use in cars are available from companies such as Map My India and Sat Nav.

While a number of different phone models now come with GPS and associated Route Guidance Software, the functionality and ease of use will vary from phone to phone. The latest development in mobiles is free Route Guidance software that is built into Android 2.0 OS that will enable a range of phones to offer full Navigation compatibility in the near future. Popular GPS based mobile handset models include the iPhone, a range of Nokia devices and other manufacturers.


While GPS Navigation systems are common in a lot of countries, it is still at a nascent market stage in India. Not too long ago, Indians only had a choice of physical maps for planning journeys and these were often outdated. While offline route planning aids are good enough to plan routes, stops etc.., nothing will beat real-time route guidance systems as one never has to get lost and this offers great peace of mind in unfamiliar locations. Imagine finding restaurants closest to one’s location in a new town or hotels to stay in or a petrol station – the Navigation system will guide the user there. For avid travelers, a Navigation system greatly enhances travel to new destinations and is a worthy investment to consider.

[This article was contributed by Vijay Ramanathan – a Technology/Gadget enthusiast and Blogger. You can follow his tweets at & his blog at ]



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