GPS Road Navigation - Essay Example

GPS Road Navigation 25 February Introduction Rapid technological advances had made our lives much easier and safer. Ironically, it can sometimes make our lives more complex too and consumers much of our time such as the ubiquitous cellphones these days. Being connected 24/7 can have its advantages as well as the drawbacks that go along with it such as distractions that keep us from focusing on our work or staying away from office concerns during precious vacation time. On the other hand, having modern technology is generally considered helpful rather than harmful. One of these technology that has a great positive impact on almost everything we do is the GPS or global positioning system. Like the Internet, it was developed by the government and was once used exclusively for military purposes only. However, its benefits had been used and made available for civilian uses and everybody had made extensive use of it these days. It is simply incredible how a proven technology can make the quantum jump from being purely military to civilian applications; today, GPS has widespread uses (McNamara 2008, p 122). I am interested in the GPS because of its extensive use of electronics and this is one of majors I will be taking up next year in my college studies. The sheer complexity of the GPS is what intrigues me and this paper is an attempt to gain further knowledge and understanding in how this magnificent technology works and the many applications in which it is used today. In essence, the global positioning system is a US-government endeavour costing it $12 billion originally to provide its military with a precise form of worldwide positioning (Trimble 2010). This space-based radio-navigation system provides accurate positioning in three-dimensional location and works in all weather conditions. The best part is that it is free (USA.gov 2010). Discussion The global positioning system has found widespread applications in all aspects of life. This means it is used in a variety of civilian uses such as in work related to farming, geology, civilian commercial aircraft, land transportation, banking services, cellular phone technology and even in the provision of emergency life-saving services. The original purpose of GPS was to provide accurate information regarding ones exact location on the high seas where there are no landmarks to provide and guide mariners on where they are and where they are going. Ancient mariners employed other methods to reckon their positions such as using the stars but this crude method only works at night and assuming weather is fine with good visibility. Most other methods likewise can give rise to errors and this can compound very quickly such that a traveller can easily get lost using the wrong set of data. Prior to GPS, there was no one perfect system that works best and people tried other ways to provide accurate measurements. An earlier and cruder version of GPS is the satellite navigation system but this cannot provide the accuracy needed to target missile systems originally intended when developing it. The SatNav does not give frequent updates on changes in the position due to fewer satellites being used and therefore has limited applicability although it is sensitive enough to the small movements in the position of the receiver. It is only GPS that can provide needed accuracy as it relies on a constellation (group) of 24 satellites orbiting 12,000 miles above the Earth. The 24 satellites circle the Earth twice each day and this is the space segment of the whole GPS system, with the other two being the land receiver control stations and the actual GPS receivers held by the users. The satellites transmit electronic signals to the control station and by a process known as triangulation, the users receiver can calculate his exact location. This is made possible by computing the time differences between when a signal was sent and when it was received. This time difference is crucial in determining the distances involved. The process of triangulation can now be done quickly using special computer software where vital data is stored and how computations are made using your present location. It will then determine the best way to your desired destination. The best way could be the shortest or fastest route between here and there, the route with least traffic or the route with best scenic views along the countryside (depending on your preference). Todays GPS is sophisticated to give the exact location (accuracy to within 10 meters) in longitude, latitude and altitude with the exact time as well (the time you were in that particular location). This wealth of data can be made possible if the users receiver (the GPS instrument or device) can lock into the positions of at least three satellites simultaneously but this will give only a 2-D position (longitude and latitude). With an electronic lock on at least four or even more satellites, the degree of information that will be made available becomes 3-dimensional to now include the altitude as well. Once the users location is fixed or determined by the lock, the users GPS unit can provide other crucial information besides time such as exact bearing, track distance, direction and speed, if one is moving to go somewhere else (Garmin 2010). GPS was specifically developed to provide exact locations at sea for use by the US submarines carrying nuclear-warhead missiles. This was during the Cold War when nuclear missiles were aimed at the enemy and accuracy depended on knowing the exact location of the missile launch. The US nuclear deterrent system was sea-based to provide it an offensive edge against Russias land-based missile system. American nuclear submarines carrying these nuclear warheads keep changing their positions to avoid detection and hence needed the GPS that was eventually developed to serve this particular purpose of accurate targeting. From that beginning, GPS was made available for civilian use entirely for free back in the 1980s and is now used in a variety of ways in whatever mode of activities such as flying, walking, biking, running, driving or sailing. This paper sees GPS at how it is used in road or land navigation. There are generally two types of GPS devices in use today. The first is the fixed GPS where it is installed by trained technicians into the boat, truck or car to be integrated with all other electronics systems in it. Sail boat owners, for example, have been using GPS to recall the previous exact location at sea where they were able to catch the most fish. This is a good example of a civilian use in navigation at sea where there are practically no landmarks. This means the GPS device cannot be easily removed as it has been installed permanently into the vehicle. The second type of GPS is the transferable or mobile unit that can be carried to some place you like. The main advantage of this unit type is mobility. You can install it anywhere you like whenever you like such as using it on your mountain bike this Sunday and then have it removed and transferred to you car on Monday when driving to the office for work. Most cars and commercial trucks today have GPS units pre-installed at the factory and now comes as a standard feature, unlike years ago when it was merely an optional and added feature. The present uses of GPS is actually an improved version of the satellite navigation in previous years. The use of space-based satellites to transmit electronic signals has improved significantly the accuracy to within 2 to 5 meters of the exact location and is now integrated with the larger sphere of activities known as Geographic Information Systems (GIS). This is now the mainstay of most land-based transportation systems worldwide (Kennedy 2002, p. 4). For example, trucks used for delivery in logistics companies utilize GPS to monitor their drivers, if they had been resting far too long in one truck stop, if they had deviated from a recommended route (this is also the best indication the truck and its valuable cargo had been hijacked), improve delivery security and inform the client of its trucks imminent arrival. The information provided by GPS is vital to individual drivers also such as when a family going on a vacation to an unfamiliar place seemed to have gotten lost along a particular stretch of a highway. There are some key things to know with regards to using GPS in road navigation. The GPS satellites transmit two types of low-power radio signals designated as L1 and L2. It is L1 that is being used for civilian purposes with a frequency of 1575.42 MHz on the UHF (ultra-high frequency band). The electronic signals travel by line of sight which means a lock on a satellite can be obtained despite the presence of clouds, glass or plastic. Similar to the cellular phone signal, it cannot penetrate buildings or mountains although it can penetrate thick foliage like when you are hiking through a mountainside. This means there are areas in which there will be no coverage such as clustered tall buildings in an urban area that hinders signal reception similar to dropped calls in cellular phone technology. Once in the clear, you will again receive a signal and get an accurate reading once more. Newer GPS devices today utilize multi-channel technology to maintain a strong lock despite these obstructions. At first start-up, the GPS device has no idea yet where it is and needs to obtain some information like the coordinates and tries to get a satellite signal. Once a signal is received, it will determine and analyse three bits of information from that signal – pseudorandom code, ephemeris data and almanac data. The first pertains to sort of an ID code of the satellite that is transmitting the signal, the second refers to the status of that satellite, the time and the current date while the third and last contains information about the satellites orbit, its position during certain times of the day and the positions of the remaining 23 satellites in the constellation. It takes some time for the GPS device to download these data from the satellite and is known as a “cold start” but if it has a battery, the data can be re-used immediately known as a “warm start”. Data downloaded in the past 4 hours is still technically valid and can be used right away in what is called as a “hot start.” It is just like any other electronic device that you are going to use for the first time such as PC or a laptop where it takes some time to boot up for the system and then download the necessary data. The software inside the GPS device is then utilized to compute for location and superimpose this on the units stored map database. There are many map data providers (private companies) today that sell all the basic information needed in road navigation that contain vital points of interest to a driver such as street names, roads, city streets, parks and all other important landmarks when travelling. The companies regularly update their map database every 4 to 6 months on specific geographical locations on all continents. It is important to choose the GPS manufacturer that is compatible with these electronic map databases for use on the device. The device must be smart enough to compensate for systemic errors and able to provide an alternate route when necessary. The largest market so far for GPS navigation systems is the rental car sector with large fleets and need to monitor where their units are and prevent car napping (Kiplinger 1996, p. 106) but there are now other land transportation uses as well, primarily that for delivery trucks. A vital function of GPS on motor vehicles is its ability to give verbal directions so that the driver will not have to take his eyes off the road. GPS is a basic technology now for logistics firms to aid driving up profits along the value chain (Brewer, Button & Hensher 2001, p. 515). It can track shipments and specific parcels to improve efficiency together with the new RFID technology. Conclusion GPS technology has gone a long way from its beginnings as a military special purpose targeting system and is continually being upgraded to other important uses. From the original intent of merely determining ones actual location, it had expanded into navigational uses and now includes tracking (monitoring movement of people and things like trucks and cars), used in mapping and precision timing (to synchronize schedules, for example). Self-guided cars that use GPS can now drive itself and you without doing anything across towns. From the US Department of Defense NAVSTAR (its official name), it is also being contemplated for use in homeland security with high-resolution imagery and intelligence-based solutions using maps (GPS World 2010). There are many creative uses for GPS where precision is required. References Brewer, Ann, Button, Kenneth John & Hensher, David A., 2001. Handbook of Logistics and Supply-Chain Management. Oxford, UK: Emerald Group Publishing. Garmin, 2010. What is GPS? [Electronic]. Available: http://www8.garmin.com/aboutGPS/ [23 February 2010]. GPS World, 18 February 2010. Navteq to Support Homeland Security [Electronic]. Available: http://www.gpsworld.com/government/emergency-response/news/navteq-support-homeland-security-9569 [24 February 2010]. Kennedy, Michael, 2002. The Global Positioning System and GIS: An Introduction. Boca Raton, FL, USA: CRC Press. Kiplingers Personal Finance, July 1996, 50 (7). ISSN 1528-9729. McNamara, Joel, 2008. GPS for Dummies. Hoboken, NJ, USA: John Wiley & Sons. Trimble, 2010. GPS Tutorial: Why GPS? [Electronic]. Available: http://www.trimble.com/gps/whygps.shtml#0 [24 February 2010]. USA.gov, 2010. Global Positioning System: Serving the World. [Electronic]. Available: http://www.gps.gov/ [22 February 2010]. Read More