Feb 052012

GPS Navigation Systems

Global Positioning system (GPS) is a device that receives signals from GPS satellites and provides device position in earth in terms of Latitude and Longitude, some device may also provide altitude those are used in aviation. Earlier GPS devices were only used by defence applications, aviation, and marine, but today it is very much common thing among mobiles, tablets, cameras and many other gadgets.


How does  GPS Navigation Systems devices Work:


A GPS device is a GPS enabled mobile, a PND (personal navigation device) or a car navigation device having a GPS receiver or antenna that serves to receive the signals from GPS satellite. These satellites are launched and managed by USA (a network of at least 24 nos. of satellite is managed) and this service for personal navigation and finding position for civilians is free.

In 1980 this service is made available for civilians by US government. A GPS receiver must be locked on to the signal of at least three satellites to calculate a 2D position (latitude and longitude) and track movement. With four or more satellites in view, the receiver can determine the user’s 3D position (latitude, longitude and altitude). Once the user’s position has been determined, the GPS unit can calculate other information, such as speed, bearing, track, trip distance, distance to destination, sunrise and sunset time and more.

GPS receiver calculates the position of device using reference of satellites with inbuilt triangulation and as per the time reference the GPS signal transmits and receives.


If a device have inbuilt maps e.g. google maps or any navigation application like sygic, tomtom, Ndrive,Garmin, mapmyindia etc. then it shows your position in map in readable format.


Assisted GPS (A-GPS) is a service that enables you to detect your position and navigate using your mobile’s service provider using GPRS/3G network. When you move from one place to another your mobile network keep track of you using the network towers. There is one cell defined by cellular operator using your position. Using this information you can get your location in maps using GPRS/3G network. But there are many draw backs of A-GPS like you get accuracy in 200-500 mtrs. So during navigation may be possible that a turn that is before 500mtr your device tells you to turn here and you may misguided by your device.

Also in some places where signals are low or lost e.g. in rural areas, in hill areas, forests etc. you cannot navigate or not able to detect your location.

A GPS provides your location in the accuracy of 5-10 mtrs. Also you may get your position in any locations. Only there is problem to get GPS signals when there is cloudy or rainy weather.

What are the uses of GPS navigation systems enabled devices:

Using GPS you can found your position if you in a new places, you can navigate e.g. in google maps in mobile just type your desired location to get direction and it will calculate the shortest route and then you can drive according to that route.

In premium navigation applications like sygic, tomtom etc. you can also get voice guided navigation that tells you when you have to take a right turn, take a u-tun etc.

Even you can found the places of interest nearby, e.g. ATM, Fuel station, Hospital, Shopping Mall, Hotels. If you are a tourist you can get information and locations about historical places, amusement parks, museum etc.

You can record your track using GPS device so that you can follow those tracks when you come back, it is very useful for a Pedestrian, a cyclist to track back their path when coming from a location.

Apps can be used in GPS navigation systems enabled smartphone/Mobiles

Google Maps

If you are having a smartphone with GPS you can use Google Maps to navigate and see you correct location. Google maps generally loads maps from your networks GPRS or 3G services. Now Google also providing you the offline cache and offline map tiles service. Using offline cache you can view the cache maps even without network connections, and using offline tile features you can download offline map tiles up to 10 no’s of 10mi square area. But there is only one drawback that this offline tiles data and information has been reduces by Google so that download memory may come down. So you will not get full information’s as like desktop map version or online Gmaps version.

In Google maps there is also a very important service that is a latitude service. Using latitude you can view locations of your friends, relatives, who are in your latitude circle. Gmaps provided you many features e.g. you can view terrain view, street view if available in your location, voice guided navigation in selected counties, you can found nearby places of interest like ATMS, restaurants, hotels etc.


Ovi Maps by Nokia– Nokia provides Ovi maps in their mobiles free of cost. Using Ovi maps you can navigate and found places of interests.

MapDroid– This is a free apps for android devices available at market, using this you can view most important highways and state highways but not providing other information and city guide etc. It is light apps can be used only for driving purpose.

Rmaps– Using Rmaps you can view the maps and your position but it is not provided you navigation facility. There is one benefit in rmaps that using Mobile atlas creator (a software for computers) you can download offline Google map tiles upto any desired size (e.g. 100X100kms.) using your computer’s broad band connection and then transfer that tile into your mobile’s SD card. Now using this downloaded tile you can view offline map and your position using ramps (very interesting and great feature).

I have mentioned in my post how to create offline google maps for rmaps using mobile atlas creator you can view this post to download your desired map tile.

Also you can download offline map tiles already made available by me for delhi/ncr and Jaipur in my previous posts.

 GPS essential app for android

 Download this app for android device from market and install, using this apps you can view satellite information that how many satellite are available and many other also, if only 1 or 2 satellite are viewed then your position cannot be determined.



Sygic/TomTom/Garmin/SatNav etc. – these are premium navigation applications providing you voice guided navigation and many other features. You can view on screen your driving speed, next coming turn, and many others. In sygic aura you can also view 3D maps of cities with 3d buildings and other historical places etc.


The devices that are not having inbuilt GPS antenna for tablets and laptops you can use external GPS antenna. After connecting this antenna to your devices, you can use your navigation application inside your laptop and tablets.




Car Navigation Systems – Some of example are Garmin, Sygic, MapmyIndia, TomTom, SatNav etc.

Navigation Devices– These devices dedicated to only navigation purpose so that you will not interfered by phone calls, sms during your navigation. Also display screen is large, some manufacturer claims that screen is also be not dull in sunlight. These are having external antenna (some may be internal) so that you will receive more powerful signals that locks very fast and not lost easily in case of cloudy or raining weather.

Some use full information regarding GPS navigation systems 

 Your GPS enabled device locked very easily and fast if you use your device internet (GPRS/3G) at the starting, I have experienced it that when I start a vavigation apps with enabling GPS antenna and GPRS it locks fast. Afetr locking you can turn off the GPRS or 3G.

Find the antenna location of your mobile using your device manual, mostly it is top back side of your device. So when you want to lock GPS turn your mobile backside and in the direction of sky. Do not cover your mobile’s backside with your hand or any other paper or cloth.

In rainy and cloudy weather it may take very long time to lock with GPS satellite some time may be failed. This time use your mobile’s GPRS/3G to navigate.

During GPS navigation mobile consumes very much of battery , so use car charger to continue charging your mobile or you can use navigation kit for your car that is having inbuilt charger and can also be connect with your car’s speaker system.

Many times GPS navigation devices can tell you a wrong route that has been closed or diverted because these maps not updated very much frequently. So also uses other devices and see the road signs, street signs also.

Although these are very good devices but do not rely them 100%, If you know that some road is always congested by traffic you can choose any other road in your navigation system by choosing via option.

Resources –  

Google Maps Android
Sygic Navigation for android