The answer to 'what is navigation?' is, shortly given as the help to change position around the world from one place to another.In the other words when we use navigation technology we are aware of the way we go to the place we want and the place that we are now. Mankind's earliest navigational experiences started even before the birth of Christ. Ancient mariners, bronze age Minoan seamen and later Vikings were probably making infrequent journeys across oceans in different routes. Of corse everybody wants to answer the question: how did they find their way across boundlessseas without any piece of integratng accelerometers and hand-held recievers which are available in commercial markets today? Normally there are still dozens of ships which were sent to the bottom by numerous navigational errors; than a new technology of radionavigation become widespread especially dıring the World War II also in military sector. In the following years many countries espacially U.S.A have operated ground-based radionavigation systems and started to move their navigational transmitters upward from the surface of the earth into outher space to get more accuracy despite the astronomical costs. The Global Positioning System (G.P.S.) is one of the most important inventions of the last century, which uses the future's preferred technology of sattelites and radionavigation, and has many applications an both the civil and military sectors.
In their long life on the earth, people learned the term navigation and apply it into their life by improving some different ways to navigate with their own works in the past. Navigation can simply defined as, the help to change position from one place to another with a knowledge of location and destination (Logsdon, 1992, p.3). Many years ago people used different ways to navigate with their little possibilities. We know that , the sun and the stars were the only helpers to the sailors in old times to find their way, from the historical writing, 'keep the great bear on his left hand.' Of Odysseus ( p.1). Of course it is not a completely
satisfactory information because there are many days that 'the great bear is hidden by the clouds' said the Englishman Alexander Neckam in 1188. By the years passed people stopped trusting the sky to find their way and simple tools were made which started by 'compass' , to find way (p.1). After these numerous studies have been done for navigation because of the importance of it in people life, and the last point has been came is the spacewide radionavigation system, GPS.
GPS is a complicated system of navigation that uses satellites and other parts to came over to the other systems in the future as well as to serve people all around the world. The more tecnical meaning of GPS can briefly be defined as a numerous client with recievers supporting system which works worldwide even spacewide with the help of the signals presented by th satellites (Logsdon, 1992, p.17). In fact the working principle is clear: accurate timing pulses and satellites ephermis constants are furnished by satellite to a worldwide class of users to fix their positions ( p.19). When doing this every law of the physics work like a chain from the satellite to the hand-held reciever with by the reciever by changing the energy in the electromagnetic waves coming from the satellites to an electrical electron flow, with an antenna in it ( Langley, April 2000, p.54).
A satellite is the most important and must be the most reliable part despite being very complex. Surprisingly it is designed to last 7,5 years or 580 million miles, but t is made from 65000 different parts. It shows one part in the direction of the earth and other in the direction of the sun during every part of it's on-orbit like just by half a degree exactness (Logsdon, 1992, p.128).
Also there are some other successful radionavigation systems compared with GPS since many years but none came near by the centurie's great invention. The amount of protection given by insurance, exactness, transmission frequences and other similar qualities are the facts
that radionavigation systems are examined and classified with each other ( p.34). Loran was one of the earliest and most succussful systems for ground based radionavigation systems. Like Loran, Omega was orginally designed as a hyperbolic radionavigation system. Other kind is that inertial navigation which is not throughly a navigation system but it is so competitive with GPS because it is so popular with different users.
Not hesistatingly, the future of the system is wide open in every area of human life for both civil and military sector from bombing accuracy to economy. Nowadays GPS is only used in some specific scientific ways, but in future as the satellites improve and increase in number it will provide many advantages to people in very interesting parts of life. For example, in the near future, maybe the sightseeing boats in California Delta can use the advantages of the GPS system which can help them to see water depths and prevent from navigation errors ( p.218), and this is only one example that will be mentioned later. Other fact is the financial part of GPS. In the future the planners do not want to stop earning enough money with useful ideas from Navstar navigation. As the project proved it's success, an investigator who works on GPS for a quarter year does not deserve any punishment agreeing european VIP (Warwick, April 1998, p.27).
GPS certainly has a great role in military sector which can improve the war tactics and produce more accurate target shooting dispite the difficulties of enemy forces and the other enemy, nature. In the past at World War II only naerly 3% of british bombs reached within 5 miles of the expected points in the quick attacks targeting the Nazi war machine. In a different way, smaller targets were bombed with more accuracy by precission munitions in Persian Gulf War with services suported by Navstar navigation satellites (Logsdon, 1992, p.192). Field test results show the advantage of the system clearly. For example static positioning which is improving day by day to aid military researchers in combats, was very successful in
recent years with very small errors ( p.193), and in bondless seas, marine navigation is the only aid source for military crafts. For example, United States coasts are controlled by GPS system which displays all comings to the shore in every weather conditions even in low sights( Glede, 2000).
Other thing is that the projected battle fields that helps generals to plan the attacks and raids before losing men and equipment as well. GPS modified operators sre very more successful in minesweeping activities with an amount of nearly 20 times for mines which were one of the major guarding units and caused numerous deaths in the past wars (Logsdon, 1992, p.195). Also %90 less tries needed to hit to eliminate Soviet radar controlled anti-aircraft gun with GPS equipped artillery batteries than others attacking same targets without the system ( p.195).
Normally military recievers are more complicated to give exact coordinates because they are usually improved by Rockwell and DoD supplements. One good reason for this is the specific targeting option for misiles. Accuracy enchantement for misiles is one of GPS's major purposes. With complex navigation systems, misiles became the one of the most important attacking systems for both ground and air targets. The reason of these's usefulness is of course it's preventing capability of losing men like in close combats as in the past. Two important kind of misiles use this system throughly and these are strategic misiles and cruise misiles which gets aid from GPS to hit the exact targets within less tries as possible.
Different than known, GPS has and will have many applications in civil sector that improve people's life and that will also be probably used by everybody in the near future. New made automobiles use the GPS technology to prevent the waste of travelling distance and causes of it as well. Exact position fixing signals of GPS are very useful for automobiles. The waste of distance travelled is %6 for non-commercial automobiles and %12 for all, and it
can be prevented by an accurate navigation. To understand the importance clearly we must know that, the distance wasting means more vehicle operating costs, extra driving time and of course additional accidents which causes millions of deaths per year ( p.214).
In addition, GPS technology will aid firms to find undergrpund sources fuel or mining elements, which are very valuable for a country, more technically and accurately of course. GPS transmitters help researchers t explore oil sources that are countrie's hearth of power and economy. Even in offshores succesful building of three dimensional underground geological shapes are the facts that direct the oceanic oil researhers ( p.211). As well as oil searchs, scientists are sure about finding new resources for country is more available if the GPS technology is used especially in the east part of the world where are rich of these kind of sources (Glede, 2000).
In the same way, with GPS, numerous crashes had been prevented caused by icebergs which can not be displayed by other systems for centurie's. Many efforts have been made to track icebergs with electromagnetic sensors on board orbiting satellites but so far, results have not been entirely satisfactory (Logsdon, 1992, p.210). For sure, everybody remind the crash of Titanic caused by an iceberg, after these words. To think clearly it can be declined that, hundreds of people in that giant ship would not be died and who knows, maybe people could be using it today for vacaion if the aciident was prevented by a little GPS reciever in the captain's pocket! Not only to prevent crashes GPS equipped systems also helps mariners to find a way in the ice by determining the thinnest parts of it to make it possible for ships to pass across frozen waters (Glede, 2000).
Other way that GPS serve people is guiding archaelogical expeditions that would show the life of pasage people and creatures more clearly. Researcher's one of the work point is the structure of the pyramids which have been made thousands of years before from thousands of
stones each with tons of weight (Glede, 2000), so GPS will help archaelogists to solve this historical mystery. Not only egyptian but also many other civilizations and living places of them are mapped with the help of the system (Glede, 2000). In a strange way dinosaur hunting also would be possible with GPS if there have been this technology hundreds of years before. To think the usefulness of the Navstar GPS you can imagine zoos including gigantic brotosaurus or like creatures (Logsdon, 1992, p.208).
In conclusion, people always upgrade their life standarts in every kind of technology. After finding the shape of the world and map it people want to know. So, the end of the navigation studies came to the world-wide eadionavigation system, GPS, which is a must celebrated invention of the century because of it's profits for human in a very wide area of life.
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