Global Positioning System - Term Paper Example

GLOBAL POSITIONING SYSTEM (GPS) Global Positioning System (GPS) Affiliation Table of Contents Table of Contents 2 3 Emergence and History 3 How GPS works/Operating 4 GPS Satellite Network 6 The Navstar GPS Group 7 GPS Position Determination 8 GPS Accuracy 8 GPS Usage and Services 9 GPS technology Future 9 Conclusion 10 Bibliography 10 Abstract GPS (global positioning system) is a satellite-based navigation arrangement that is made up of a communication network of 24 satellites. Additionally, these 24 satellites are placed into an orbit with the U.S. DoD (Department of Defense). In addition, the global positioning system was initially planned for military applications, however in the 1980s, the administration of US made the system accessible for civilian utilization. Moreover, the global positioning system operates in any weather state, anywhere in the globe, 24 hours a day. Also, there are no payment fees or setup expenditures to make use of the GPS. The technology is owned by the United States that offers users through navigation, positioning as well as timing services. This system is composed of three segments that are control segment, the space segment and the user segment. The United Sates Air Force maintains, develops as well as operates the space and control segments (Bajaj, Ranaweera, & Agrawal, 2002). This paper presents a detailed overview of global positioning system. This paper will outline the history, advantages and disadvantages of the global positioning system. Emergence and History Initially GPS system was designated the navigation system with timing and ranging (or NAVSTAR) global positioning system. Additionally, US Department of defense initiated this project to offer round-the-clock and all-weather navigation abilities intended for sea, military ground as well as air forces. In addition, with the development of global positioning system it has become an integral asset in several civilian applications as well as industries around the world, comprising recreational utilization (for example aircraft, boating, hiking), business vehicle fleet tracking, as well as surveying. However, the general development of global positioning system was initiated by LORAN and the Decca Navigator developed ultimately in 1940s, as well as employed throughout World War II. Additionally, to attain precision requirements, GPS employs rules and regulations of general relativity to make right the satellites atomic clocks. In addition, by seeing these parallel developments in the GPS technology, in 1960s it was recognized that a superior system could be developed by producing the most excellent technologies from 621B, Timation, Transit and SECOR in a multi-service program. Thus, a meeting of approximately 12 military officers held at the Pentagon in 1973. In which they decided to create a DNSS (defense navigation satellite system). Thus, after one year of that meeting the DNSS program was called as Navstar. Additionally, through the individual satellites started associated with the name Navstar (as by the predecessors Timation and Transit, a more completely encompassing name was employed to recognize the constellation of Navstar satellites. Moreover, its more suitable name was Navstar-GPS that was afterward shortened and taken as simply GPS (GPS.GOV, n.d) & (garmin, 2010) & (gisdevelopment, 2010) & (NASA, 2010). How GPS works/Operating While talking about GPS system’s working the GPS reserved satellites circle around earth twice a day in an extremely exact orbit as well as transmit data and information signal to earth. In this scenario, Deichmann & Wood (2001) stated global positioning system receivers obtain this data and information and makes use of the triangulation to compute the users precise location. Fundamentally, the Global positioning system receiver evaluates the time a signal that was transmitted through a satellite and the time it was received. In this way, the time difference informs the GPS receiver how distant away the satellite is. Additionally, at the present through the distance measurements from a few more satellites, the receiver is able to decide the users position as well as display it on the units electronic map (Deichmann & Wood, 2001). In addition, a global positioning system receiver has to be locked on to the signal of at least three satellites to compute a 2D location (longitude and latitude) as well as track movement. Moreover, with four or more satellites in a location, the receiver is able to decide the users 3D position (longitude, latitude as well as altitude). Once the users location has been assessed, the GPS unit is able to estimate other information, like that bearing, speed, trip distance, track, sunrise sunset time, distance to destination as well as other lot more facts (Deichmann & Wood, 2001), (Griffin, 2008) & (Schieger & Glaser, 2005). Figure 1- Position Estimation Source [http://www.pocketgpsworld.com/howgpsworks.php] GPS Satellite Network There is a net of 24 different GPS reserved satellites in the space. This overall structure of satellites facilitate in the proper communication of the GPS. Additionally, the global positioning system satellites distribute signals to a global positioning system receiver. In addition, these GPS receivers inertly receive satellite information signals and they do not broadcast as well as need an unobstructed location/position of the sky. Thus, they can simply be employed successfully outdoors. However, early receivers did not carry out well inside forested regions or near tall buildings however after that new technology based GPS receiver which were designed like MTK, SiRFStarIII, etc have addressed this issue and enhanced performance as well as sensitivity markedly. Furthermore, global positioning system’s operations are reliant on an extremely correct time reference, that is offered by atomic clocks on the satellites (garmin, 2010) & (gisdevelopment, 2010) & (NASA, 2010). Figure 1- GPS Satellite Network [Source-http://www.pocketgpsworld.com/howgpsworks.php] The Navstar GPS Group Every GPS satellite broadcasts data that points out its location as well as the present time. In this scenario SCHWIEGER & GLÄSER (2005) outlined that every global positioning system satellites synchronize operations as a result these repeating signals are broadcasted and distributed concurrently. If the signals from the global positioning system satellites are moving at the speed of light and received at a GPS receiver at a little different time then the reason would be that a number of satellites are much more away than others. However, the distance to the global positioning system satellites could be measured by estimating the amount of time it takes for their signals to deliver to the receiver. Additionally, when the GPS receiver calculates the distance to at least four GPS satellites, it is able to compute its location in three dimensions (Schieger & Glaser, 2005). In addition, in the space there are 24 operational global positioning system satellites and these satellites are positioned in a number of spares. However, the satellite of US DoD, orbit have a period of 12 hours (e.g two orbits for each day) at a height of approximately 11,500 miles with moving speed of at near 2,000mph. However, at earth, ground stations are established to track and accurately position each satellites orbit. The GPS signals are broadcasted at a power equal to a 50 watt home light bulb. Moreover, those transmitted signals have to pass throughout the space as well as our atmosphere before they arrive at SATNAV after a drive of 11,500 miles (garmin, 2010), (Griffin, 2008) & (gisdevelopment, 2010). GPS Position Determination Deichmann & Wood (2001) describe that a global positioning system receiver is familiar with the location of the satellites for the reason that that information is incorporated in the broadcasted ephemeris data. Thus, by determining how far away a GPS satellite is, the GPS receiver as well is familiar where it is located somewhere on the outside of an imaginary sphere centered at the satellite. In this way, it finds out the sizes of a number of spheres, one intended for every satellite as well as consequently be familiar with the receiver that is located where these spheres intersect (Deichmann & Wood, 2001) & (NASA, 2010). GPS Accuracy The accuracy of a GPS system is really important. The accuracy and correctness of a position that is calculated by the GPS depends on the kind of receiver. Additionally, the majority of consumer GPS tracking system units have an accuracy of about plus-minus 10 meter. On the other hand, remaining receivers utilize a technique acknowledged as DGPS (Differential GPS) to get a great deal superior accuracy. In addition, differential GPS needs an extra receiver fixed at a recognized location nearby. Moreover, the explanations made by the stationary receiver are utilized to make accurate positions determined by the roving units, creating accuracy and correctness greater than 1 meter (Deichmann & Wood, 2001) & (Bajaj, Ranaweera, & Agrawal, 2002). GPS Usage and Services Bajaj, Samantha Lalinda Ranaweera, & Agrawal (2002) discuss that GPS satellites provide services to both civilian and military users. Additionally, a global positioning system can be utilized in a lot of ways in our lives. However, the biggest and main purpose for which GPS technology was developed is for militarily use. In addition, at the present, approximately whole worlds are making use of this technology for air, sea and land militarily purposes. On the other hand in case of civilian use of GPS service is freely obtainable to the entire types of users on continuous, global basis. In addition, the new and advanced emergency services are also making use of the GPS technology to detect the exact place of disaster as well as this technology is openly utilized by people to navigate in city and streets. Moreover, these GPS receives are widely available in vehicles and cars for perfect navigation. Here another major usage of the GPS technology is in the oceans since big ships and rafts are utilizing the GPS based navigation for locating the right place in the huge sea (Bajaj, Ranaweera, & Agrawal, 2002). GPS technology Future US DoD is dedicated to a widespread modernization program comprising the establishment of a second as well as a third civil signal on global positioning system satellites. Additionally, the 2nd civil signal will enhance the correctness and accuracy of the civilian service as well as up hold a number of safety-of-life applications. On the other hand, the 3rd signal will additionally improve civilian potential as well as is mainly designed for safety-of-life applications, like that for aviation and emergency services (GPS.GOV, n.d) & (Ranfl, 2004). Conclusion Global positioning system technology has offered us a new era of technology in which we are no longer stranger to any part of world. In the present age the technology of the global positioning system is going to facilitate in lots of areas of life. In addition, the military and civilian uses of this technology are emerging day by day and offering more enhanced technology artifacts. Moreover, we are expecting more enhancements in these grounds. Bibliography Bajaj, R., Ranaweera, S. L., & Agrawal, D. P. (2002). GPS: Location- Tracking Technology. Computer Volume 35, Issue 4 , 92-94. Deichmann, U., & Wood, S. (2001). GIS, GPS, AND REMOTE SENSING. Appropriate Technology for Sustainable Food), Brief 7 of 9, August 2001 . garmin. (2010). What is GPS? Retrieved 05 2, 2010, from http://www8.garmin.com/aboutGPS/ gisdevelopment. (2010). Global Positioning System. Retrieved May 03, 2010, from http://www.gisdevelopment.net/Tutorials/tuman004.htm GPS.GOV. (n.d). The Global Positioning System. Retrieved May 03, 2010, from http://www.gps.gov/systems/gps/index.html Griffin, D. (2008, June 27). How does the Global Positioning System work ? Retrieved May 04, 2010, from Pocketgpsworld.com: http://www.pocketgpsworld.com/howgpsworks.php NASA. (2010). Global Positioning System (GPS). Retrieved May 03, 2010, from http://msl.jpl.nasa.gov/Programs/gps.html Ranfl, U. (2004). Photogrammetry and GPS technology assisting the acquisition of road geolocation and geometry. DFG CONSULTING, d.o.o., Ljubljana, Slovenia. Schieger, V., & Glaser, A. (2005). Possibilities of Low Cost GPS Technology for Precise Geodetic Applications. From Pharaohs to Geoinformatics FIG Working Week 2005 and GSDI-8 Cairo, Egypt April . Read More