A Comprehensive Analysis: How Global Positioning Systems Work

This essay provides a detailed overview of Global Positioning Systems (GPS), explaining their functionality, significance, and role in modern life. It begins by describing the core components of a GPS, including the user segment, control segment, and space segment, and how these elements work together to determine a user's exact position. The paper discusses the trilateration method used by GPS receivers to calculate location based on signals from multiple satellites. It highlights the diverse applications of GPS in areas such as vehicle navigation, space communication, emergency services, and national security. Furthermore, the essay touches upon the concept of Selective Availability (SA) and its discontinuation, which significantly improved GPS accuracy for civil and commercial users. In conclusion, it emphasizes the indispensable role of GPS technology in various fields, from transportation and communication to health and crime prevention, underscoring its continuous advancement and increasing importance in resource management.

Running head: HOW DO GPS SYSTEMS WORK?
How Do GPS Systems Work?
Name of the Student:
Name of the University:
Author Note:

How Do GPS Systems Work? 1
Objective:-
Global Positioning System (GPS) is a technological tool that simplify life by empowering
oneself to find his/her destination without getting lost.

How Do GPS Systems Work? 2
Introduction:-
GPS is a space based satellite navigation system that determines one’s exact position near
or on the surface of earth, anytime, anywhere, in any weather condition irrespective of its
location. The system is of prime importance to military, civil and commercial users around the
world (du Plessis & Van Niekerk, 2014). This paper initially describes the GPS, followed by the
discussion about the functionality of the GPS. Then, it highlights about the significance and role
of GPS in our daily life. Further, it discusses about selective availability. Finally, it draws
conclusion about the effectiveness of GPS inhuman life.
Global Positioning System (GPS):-
GPS is referred to as a satellite navigation system, which comprises of three elements -
the user segment (receivers), the control segment (ground stations)and the space segment
(satellites) to find and locate an object’s ground position through positioning, navigation, and
timing services ("GPS.gov: GPS Overview", 2018). In earlier days, US government developed it
for military navigation and nowadays anyone having a GPS enabled-device can receive the
satellites broadcast signals. Both the control as well as space segments are developed, operated
and maintained by the Air Force of United States. The receivers or user segment is referred as
GPS user equipment, which determines user position and time by using the transmitted
information based on the signals received from the GPS satellites. The control segment tracks
and maintain the GPS satellites, uploads modified navigational data along with adjustment of
satellite clocks through global monitor as well as control systems. The space segment contains a
group of stars that provides the current GPS satellite position and time through one-way signal
transmission. The satellites are arranged and divided into six orbital planes. Each plane is spaced
equally and the space of each plane four slots. Each slot is by baseline satellites. This

How Do GPS Systems Work? 3
arrangement allows users to view at least four satellites from almost any point of earth and each
GPS satellite transmits information at regular intervals about the user’s position and the current
time. The user’s GPS receiver catch these signals and compute it distance with each satellite and
based on that the time that will be taken by the message to arrive is determined. Based on the
information about the distance of at least three satellites, the user’s GPS receiver can track and
find its position or location using the trilateration method. Trilateration determines absolute or
relative object or user location of through measurement of distance using the geometry of
triangles, circles, spheres (Porter, 2016). GPS satellites broadcast their signals in space with a
certain accuracy and it depends on factors such as receiver design features, satellite geometry,
atmospheric conditions, signal blockage (Venkatraman, Panther & Yuen, S. G. J. (2017).
GPS is particularly useful in space communication as it can be used to find the speed,
attitude and position of the International Space Station. GPS also provides more precise speed
and position data compared that previous data that had been available. National Aeronautics and
Space Administration (NASA)’s future mission of advancement in space science through space
exploration and scientific discovery demands the development and implementation various GPS
applications ("NASA - NASA's Utilization of Global Positioning System (GPS)", 2018).
GPS are a great tool for individuals to use in their every day life:-
GPS is most commonly used in the system of vehicle navigation and in space-age
satellite technology as well as in interactive maps for outdoors. Still it has other practical uses
such as knowing the position of children, keeping track of elder members of the family, getting
emergency road side assistance at a touch of a button from the vehicle (Salim & Idrees, 2013).
GPS implementation can saves lives as such implementation can forecast whether,
monitor earthquake, protect environment, speed up delivery of emergency services, prevent

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transportation accidents, weather forecasting, earthquake monitoring, disaster relief,
environmental protection along with preventing transportation accidents ("GPS.gov:
Applications", 2018).
GPS provides benefits to both commercial and civil users around the world in several
different applications in areas such as emergency response, telecommunications, navigation of
road, rail, marine and air along with mining, oil exploration and many more. Finally, GPS plays
vital role in national security of United States and its advanced applications are embedded into
almost every side of military operations of the United States. In addition, almost every assets of
the military are equipped with GPS.
Selective Availability (SA):-
It was referred as the degradation of intentional implementation of public GPS signals for the
sake of national security ("GPS.gov: Selective Availability", 2018). During the year 2007, the
government of Unites States decided to exclude the SA feature in creation of all GPS satellites of
future generation. The decision to discontinue SA would make the GPS much more responsive in
a global way to civil as well as commercial users. The decision is made on the recommendation
of the defence secretary while coordinating with the transportation and state departments, the
director of Central Intelligence as well as agencies and department of several other executive.
They ascertained that discontinuation of SA will serve the global safety, transportation,
scientific, commercial interests. In addition, civil users would realize the substantial
improvement of the GPS accuracy after the discontinuation of SA. The decision to discontinue
SA has been integrated with the United States continuous efforts to upgrade the utility of the
military systems that use GPS. In addition, the threat assessments supports the decision and

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infers that fixing zero to SA would have negligible effect on national security. ("GPS Selective
Availability", 2018).
Conclusion:-
In conclusion, it can be said that GPS is a modern technology and its importance in daily
life is cannot be denied. Moreover, in the dynamic world of today, the applications of GPS is
rapidly and quickly increasing. The major goal of GPS is to solving many human problems by
making the tasks easy to execute. From the above discussion, it is found that GPS applications
have great significance in field or areas such as transportation, communication health, and crime.
It is necessary to figure out the how GPS is advantageous in the diverse field of research and
development as GPS continues to progress and direct even more easiness in field of resources
management.

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References:-
du Plessis, H., & Van Niekerk, A. (2014). A new GISc framework and competency set for
curricula development at South African universities. South African Journal of
Geomatics, 3(1), 1-12.
Porter, W. M. (2016). Global Positioning System.
Salim, K. A., & Idrees, I. M. (2013). Design and Implementation of Web-Based GPS-GPRS
Vehicle Tracking System. International Journal of Computer Science Engineering &
Technology, 3(12).
Venkatraman, S., Panther, H. G. A., & Yuen, S. G. J. (2017). U.S. Patent No. 9,597,014.
Washington, DC: U.S. Patent and Trademark Office.
GPS.gov: Selective Availability. (2018). Retrieved from
https://www.gps.gov/systems/gps/modernization/sa/
GPS Selective Availability. (2018). Retrieved from https://www.navcen.uscg.gov/?
pageName=gpsSelectiveAvailability
NASA - NASA's Utilization of Global Positioning System (GPS). (2018). Retrieved from
https://www.nasa.gov/directorates/heo/scan/communications/policy/GPS_Utilization.html
GPS.gov: GPS Overview. (2018). Retrieved from https://www.gps.gov/systems/gps/
GPS.gov: Applications. (2018). Retrieved from https://www.gps.gov/applications/