13-07-2012, 01:04 PM
GPS NAVIGATION IN MOBILES:
[attachment=27542]
Introduction:
Since earliest time, humankind has concerned itself with where it’s at and where it’s going. Some of the earliest techniques that travelers used were simple rock cairns marking the trail, either for finding their way back, repeating their path, or for others to follow. This technique is still used today. The problems with it, however, are obvious. What do you do if snow covers them. How do you identify one path vs. another. In any event, the vagaries of nature insure that the markers are not likely to last very long unless they are indeed substantial (as many were).
A better method was to record this spatial information on a clay
tablet or piece of parchment which could be copied and handed from one person to another. We call these maps. The first recorded maps date backto the Mesopotamians some 5,000 years ago, constituting a revolution in geographic positioning that has enjoyed widespread use ever since. While the technology behind cartographic techniques has improved many orders of magnitude over the centuries, conceptually they remain fundamentally the same even today.
Today, we live in a world of precision. We expend great amounts
of intellectual and monetary currency on ever-smaller units of measure-
ment. Knowledge of where we are and where we are going has, for the
past several thousand years, relied on highly trained and skilled surveyors. The science of surveying has achieved phenomenal levels of precision.But, unfortunately, only for those very few whose needs have outweighed the ever-increasing cost necessary to achieve that precision
What Is GPS:
We begin with the most basic question: What is the Global Positioning System. The Global Positioning System is a space-based navigation and positioning system that was designed by the U.S. Military to allow a single soldier or group of soldiers to autonomously determine their position to within 10 to 20 meters of truth. The concept of autonomy was important in that it was necessary to design a system that allowed the soldier to be able to determine where they were without any other radio (or otherwise) communications. In other words, with a single, one-way receiver whose use could not be detected by potential hostiles.
Since the U.S. Military is truly a global force, it was further necessary that the system provide worldwide coverage, and that the coverage be available 24 hours a day. At the same time, it had to be militarily safe in that the U.S. Military had to have the ability to deny any hostiles’ use of the system without degrading their own use.
Ultimately, it is planned that each soldier and each military vehicle will be equipped with a GPS receiver. Therefore, it was necessary that the receivers be sufficiently low in cost to meet this end. Once all soldiers are so equipped, dependence on all other systems could eventually be phased out.
Evolution of the GPS:
During the late 1950’s and early 1960’s, the U.S. Navy sponsored two satellite-based positioning and navigation systems:
Transit and Timation.The Transit system became operational in 1964 and was madeavailable to the public in 1969. Timation was a prototype system that never left the ground.
Simultaneously, the U.S. Air Force was conducting concept studies for a system called the System 621B.Ground tests were performed to validate the concept but before the system could be implemented, the U.S.Deputy Secretary of Defense, in April 1973, designated the Air Force as the executive service to coalesce the Timation and 62 1B systems into a single Defense Navigation Satellite System (DNSS). From this emerged a combined system concept designated the Navstar(for Navigation System with Timing And Ranging)Global Positioning System,or simply GPS.
The 1970’s saw the implementation of Phase I, the concept validation phase, during which the first prototype satellites were manufactured and tested. The first functional Navstar prototype satellite launch occurred in June 1977, and was called the NTS-2 (Navigation Technology Satellite 2, which was actually a modified Timation satellite). While the NTS-2 only survived some 7 months, the concept was shown to be viable, and in February 1978 the first of the Block I Navstar satellites was launched. In 1979, Phase II, full-scale development and testing of the system, was implemented with nine more Block I satellites launched during the following six years.Civilian access to the GPS signal, without charge to the user, was formally guaranteed by President Reagan in 1984as a direct response to the shoot-down of the Korean Airline Flight KAL-007 in 1983, when it strayed over the Soviet Union. The launch of thefirst of the production Block II satellites occurred five years later, in February 1989
GPS Addresses:
In December 1993, the Department of Defense declared Initial Operational Capability (IOC) for the system, with the minimum combined total of 24 Block I and Block II satellites in their proper design orbits and fully functional.
Finally, in July 1995, with a full constellation of 24 Block II satellites operating in orbit, the DoD declared Full Operational Capability(FOC) for the system.
Today, the system is fully operational, providing positioning and navigation service to virtually anyone anywhere on the globe. In a sense, it has allowed us to give every centimeter of the surface of the planet its own unique address that can be understood by anybody through the use of a universal geocoordinate system. It could be in the not too distant future that you’ll find yourself inviting a friend to your home by saying something like “. . .sure, come on over. My address is 39°45’ 16.174634"N by you can’t miss it." And the fact is they couldn’t, because on the entire planet there is no other place that shares that same address.It is yours, yours alone, and there’s no mistaking it. Seem farfetched. We’ll see. It’s hard to argue with the level of success that the global positioning system is currently enjoying. As we’ll discuss later, the costs of receivers are plummeting. They have become consumer items
that, at the low end, cost less than the typical low-priced VCR. So... why not.
[attachment=27542]
Introduction:
Since earliest time, humankind has concerned itself with where it’s at and where it’s going. Some of the earliest techniques that travelers used were simple rock cairns marking the trail, either for finding their way back, repeating their path, or for others to follow. This technique is still used today. The problems with it, however, are obvious. What do you do if snow covers them. How do you identify one path vs. another. In any event, the vagaries of nature insure that the markers are not likely to last very long unless they are indeed substantial (as many were).
A better method was to record this spatial information on a clay
tablet or piece of parchment which could be copied and handed from one person to another. We call these maps. The first recorded maps date backto the Mesopotamians some 5,000 years ago, constituting a revolution in geographic positioning that has enjoyed widespread use ever since. While the technology behind cartographic techniques has improved many orders of magnitude over the centuries, conceptually they remain fundamentally the same even today.
Today, we live in a world of precision. We expend great amounts
of intellectual and monetary currency on ever-smaller units of measure-
ment. Knowledge of where we are and where we are going has, for the
past several thousand years, relied on highly trained and skilled surveyors. The science of surveying has achieved phenomenal levels of precision.But, unfortunately, only for those very few whose needs have outweighed the ever-increasing cost necessary to achieve that precision
What Is GPS:
We begin with the most basic question: What is the Global Positioning System. The Global Positioning System is a space-based navigation and positioning system that was designed by the U.S. Military to allow a single soldier or group of soldiers to autonomously determine their position to within 10 to 20 meters of truth. The concept of autonomy was important in that it was necessary to design a system that allowed the soldier to be able to determine where they were without any other radio (or otherwise) communications. In other words, with a single, one-way receiver whose use could not be detected by potential hostiles.
Since the U.S. Military is truly a global force, it was further necessary that the system provide worldwide coverage, and that the coverage be available 24 hours a day. At the same time, it had to be militarily safe in that the U.S. Military had to have the ability to deny any hostiles’ use of the system without degrading their own use.
Ultimately, it is planned that each soldier and each military vehicle will be equipped with a GPS receiver. Therefore, it was necessary that the receivers be sufficiently low in cost to meet this end. Once all soldiers are so equipped, dependence on all other systems could eventually be phased out.
Evolution of the GPS:
During the late 1950’s and early 1960’s, the U.S. Navy sponsored two satellite-based positioning and navigation systems:
Transit and Timation.The Transit system became operational in 1964 and was madeavailable to the public in 1969. Timation was a prototype system that never left the ground.
Simultaneously, the U.S. Air Force was conducting concept studies for a system called the System 621B.Ground tests were performed to validate the concept but before the system could be implemented, the U.S.Deputy Secretary of Defense, in April 1973, designated the Air Force as the executive service to coalesce the Timation and 62 1B systems into a single Defense Navigation Satellite System (DNSS). From this emerged a combined system concept designated the Navstar(for Navigation System with Timing And Ranging)Global Positioning System,or simply GPS.
The 1970’s saw the implementation of Phase I, the concept validation phase, during which the first prototype satellites were manufactured and tested. The first functional Navstar prototype satellite launch occurred in June 1977, and was called the NTS-2 (Navigation Technology Satellite 2, which was actually a modified Timation satellite). While the NTS-2 only survived some 7 months, the concept was shown to be viable, and in February 1978 the first of the Block I Navstar satellites was launched. In 1979, Phase II, full-scale development and testing of the system, was implemented with nine more Block I satellites launched during the following six years.Civilian access to the GPS signal, without charge to the user, was formally guaranteed by President Reagan in 1984as a direct response to the shoot-down of the Korean Airline Flight KAL-007 in 1983, when it strayed over the Soviet Union. The launch of thefirst of the production Block II satellites occurred five years later, in February 1989
GPS Addresses:
In December 1993, the Department of Defense declared Initial Operational Capability (IOC) for the system, with the minimum combined total of 24 Block I and Block II satellites in their proper design orbits and fully functional.
Finally, in July 1995, with a full constellation of 24 Block II satellites operating in orbit, the DoD declared Full Operational Capability(FOC) for the system.
Today, the system is fully operational, providing positioning and navigation service to virtually anyone anywhere on the globe. In a sense, it has allowed us to give every centimeter of the surface of the planet its own unique address that can be understood by anybody through the use of a universal geocoordinate system. It could be in the not too distant future that you’ll find yourself inviting a friend to your home by saying something like “. . .sure, come on over. My address is 39°45’ 16.174634"N by you can’t miss it." And the fact is they couldn’t, because on the entire planet there is no other place that shares that same address.It is yours, yours alone, and there’s no mistaking it. Seem farfetched. We’ll see. It’s hard to argue with the level of success that the global positioning system is currently enjoying. As we’ll discuss later, the costs of receivers are plummeting. They have become consumer items
that, at the low end, cost less than the typical low-priced VCR. So... why not.