BA8605 : Advance in GPS System : GPS Technology

Introduction:

This assignment mainly focuses on advance in GPS system. Previously tracking a device was difficult however, with the advancement of technology and discovery of the GPS system, tracing a device has become significantly easy (Salvemini, 2015). Nowadays mostly all electronic devices like mobile phones has a GPS system installed in it. The signals that they receive from the GPS satellites help them to calculate the distance from them and finally locate their position on Earth. The system is advancing day by day and NASA is now planning to replace all the geostationary satellites with GPS satellites. They find application in our daily life. Most of the people now utilize the online booking service of cabs. They use GPS system to locate position of the person who has booked the cab. The following paragraphs will describe in details the working principle of the technology, the future scope followed by advantages and disadvantages of the system.  

GPS technology:

The GPS technology also known as the Global Positioning System is the result of technology advancement that helps the system to locate a user, using a particular band of radio frequency. The speed, location and time of the user can be traced with high level of accuracy. It is mainly composed of a group of satellites revolving around the Earth owned by the United States government. The U.S. Department of Defense first used the GPS system. It is also known as NavStar because it is Global navigation satellite system. The whole system consists of mainly three components: GPS satellite that sends signal to the receiver via space, the GPS receiver that receives the signal and the complex computer software that helps to decode the data and locate the receiver accurately.  

Working Principle:

Global Positioning System works on the principle of signal interception. For locating a GPS receiver, the system utilizes at least four satellites at a time that sends information about its position and time at regular intervals. These signals travelling at the speed of light are then intercepted by the receiver that calculates the distance of each satellites depending on the time taken by the signals to reach the receiver. Once the receiver has all these information, the GPS system can track the location of the receiver.

Another method by which GPS works is trilateration. Suppose three satellites are observing a GPS receiver on the Earth surface. If the distance from satellite A is known then the user must be somewhere within the covering area of the satellite. The same method is applied to other two satellites, satellite B and satellite C. From the intersection point of covering area of the satellites, the user can be located accurately.  The following diagram will explain trilateration clearly.

The number of satellites that are observing a particular GPS receiver is directly proportional to accuracy. More the number of satellites more is the accuracy. The GPS tracking system has number of applications. One of the main application is the tracking of a cell phone.

How it is used now or will be used in the future

GPS tracking system for Mobile phones:

The tracking system for mobile phone utilizes the cell phone company that sends processed data to the mobile phone. In the beginning, the cell phone company receives some information from the cell phone with the help of cellular towers that can hear the cell phone, then switches from cellular back to phone to receive raw information (Chang and Fang, 2014). The phone then sends this raw data back to the phone company that processes the data and finally sends the location to cell phone.

Active car tracking system:

The GPS tracking system is nowadays used in active car tracking system. It is a type of tracking system that gives real time data. The data is transferred through emails or fax that reports the real-time location. This is significantly useful for organizations that want to manage their vehicles and drivers to prevent theft and other malicious activities. It also finds application in rescuing the vehicle in case of an accident, monitor the consumption of fuel, the speed of the vehicle and distance that it covers in a particular time (Lee Tewolde and Kwon, 2014). For example, in case of an accident, the concerned companies will be able to gain information on the speed of the cars at which it was being driven.

Future scope of GPS:

GPS can be used for space applications in the future. NASA is planning to build specialized GPS receivers that will help their tracking stations to track faster. It will help achieve a number of future missions of geostationary satellites. The future GPS receivers that are being developed by NASA are The Navigator receiver and the BlackJack. The future Global Positioning system will be able to track the GPS receivers with more accuracy and reliability.   

Advantages of the GPS system:

The advantages of GPS over the existing technologies are as follows:

• The Global Positioning System makes use of satellites, therefore, the signal is available anywhere on Earth and the users can use the service all the day round.
• No charges are applied on the user to subscribe for GPS service, as all the cost is bearded by the US government. The US defence maintains and upgrades the system.
• It does not require any manual calibration as all the calibration is done by itself, therefore, it becomes easy for the user to use the system.
• The system can be used in other application like mapping the location, which is extensively used for cars, performance analysis used in sports and so on.  
• One of the biggest advantage of GPS is that it allows user to find a specific location such as a nearby restaurant or petrol pumps that falls within specific meters of distance from the current location.
• The Global Positioning System can also be used to give alerts for weather and traffic (Arunvijay and Yuvaraj, 2014). For example, during adverse weather conditions or in case of an accident, the GPS will provide alert if a GPS system be installed in the cell phone. They even provide an alternate route along with the alerts. However, it cannot be received on time because this feature of GPS does not provide real time data.  

Disadvantages or potential disadvantages:

The disadvantages are as follows:

• The main disadvantage of GPS is the use of signals for locating the receiver. GPS makes use of the radio frequencies that are prone to interference. Due to this interference, the signals might not give the accurate information. The signals can also be lost due to attenuation, therefore, the information that is provided might not be actual.
• The system totally depends on satellites to gain data. However, satellites have longevities of about 30 years (CHOW-FRASER, 2014). At the end of their lifecycle, they might not perform well. This can cause disruption in function and the information received from the satellite might not be accurate.
• The system trusts on batteries, therefore, when the batteries get drained out the system cannot perform its work properly.
• The cost of the system with a number of features is costly and therefore it becomes a major issue to install them. However, systems with less features do not perform efficiently.
• The signals coming from the GPS system travel at the speed of light. However, the path through which it travels causes the speed of the signal to slow down. Therefore, it causes complications while correction.
• Sometimes the signals coming from the GPS satellites are bounced and the receiver receives the bounced signal.   

Conclusion:

From the above discussions, it can be concluded that GPS system is useful in tracking all GPS receivers. The system makes use of signal interception and trilateration to locate position of device. The system has a number of application like tracking a mobile phone, active car tracking system and so on. However, there are a number of advantages and disadvantages of the system. No charges are applied on the subscriber however, the cost of the system with a number of features is high.

References:

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Arunvijay, D. and Yuvaraj, E., 2014. Design of Border Alert System for fishermen using GPS. International Journal of Students' Research in Technology & Management, 2(2), pp.67-70.

Chang, D.C. and Fang, M.W., 2014. Bearing-only maneuvering mobile tracking with nonlinear filtering algorithms in wireless sensor networks. IEEE Systems Journal, 8(1), pp.160-170.

CHOW-FRASER, R.J.C.P., 2014. Use of GPS loggers to enhance radio-tracking studies of semi-aquatic freshwater turtles. Herpetological Conservation and Biology, 9(1), pp.18-28.

Elprocus.com. (2018). [online] Available at: https://www.elprocus.com/wp-content/uploads/2013/07/GPS-Circuit.png [Accessed 6 Aug. 2018].

Gpsintegrated.com. (2018). Mobile Phone(Smartphone) Tracking | GPS Integrated - GPS Tracking & Fleet management. [online] Available at: https://www.gpsintegrated.com/products-3/mobilephonesmartphonetracking [Accessed 6 Aug. 2018].

Lee, S., Tewolde, G. and Kwon, J., 2014, March. Design and implementation of vehicle tracking system using GPS/GSM/GPRS technology and smartphone application. In Internet of Things (WF-IoT), 2014 IEEE World Forum on (pp. 353-358). IEEE.

NASA. (2018). Global Positioning System History. [online] Available at: https://www.nasa.gov/directorates/heo/scan/communications/policy/GPS_History.html [Accessed 6 Aug. 2018].

Salvemini, M., 2015. Global positioning system. International Encyclopedia of the Social & Behavioral Sciences, pp.174-177.

Gps.gov. (2018). GPS.gov: Image Library. [online] Available at: https://www.gps.gov/multimedia/images/ [Accessed 8 Aug. 2018].