GPS Navigation System – How It Works
The Global Positioning System (GPS) was originally developed by the US Military who launched satellites (the first satellite was launched in 1978) into orbit. The system consists of a network of between 24 and 32 satellites orbiting the earth at about 7000 mph, in a precise manner, two times every day.
In the early days only the military could track the signals but in the 1980’s it was opened up to the general public.
Before we get into the specifics it is important to realize that the use of the satellite network is free, there is no subscription required.
The other benefit is the system is essentially unaffected by weather and it is accurate anywhere in the world. Some might recall the Loran system which was popular with boaters before GPS became popular.
Loran was capable of providing a very accurate position but only in limited areas where the transmission of signals was sufficient and provided the weather was not adverse.
GPS transmission satellites orbit the earth in a very precise and constant manner. As they orbit 12,000 miles above, they transmit radio signals 24 hours a day, every day. The receivers we use simply receive the transmitted signals and compare the time the signal was transmitted against the time it was received. Knowing the signals travel at a fixed rate of speed makes it easy to calculate how far the satellite and the receiver are from each other.
If this process were done with only one satellite the result would not be useful for us since it would only indicate a possible arc of a position. To provide accuracy the receiver has to receive signals from a minimum of 3 satellites.
In actual use, the receivers typically track the signals from many more satellites.
In order to provide data like speed, direction, distance traveled, etc. the receiver repeats the position calculation on a continual basis and thus updates the position and other data. The signal transmitted includes the satellites ID, the satellites position at any given time and the date and time.
Accuracy of the receivers has improved with technology advances to an average of about 15 meters. In real practice it is common to see accuracy within a meter or two, at least at times.
When GPS was opened up for public use the signal was intentionally degraded by the Government which was referred to as Selective Availability (SA). SA has been discontinued so civilians now enjoy full accuracy of the system.
Technology referred to as Wide Area Augmentation System (WAAS) available with some receivers improves accuracy to about 5 meters. Receivers equipped with Differential technology apply corrections to the data based on other known references.
The end result is accuracy and functionality of GPS receivers to the point we all can rely upon. As a result we now see and enjoy GPS watches, auto and boat GPS navigation systems, GPS cell phones.
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Mobile GPS Tracking
Categories: Car GPS System Tags: Navigation, System, Works
Track any cell phone by using GPS tracking system
Cell phone GPS tracking
Ever been stunned by the disappearance of your mobile phone when you were quite sure you had locked it up securely!! If you had installed a GPS mobile phone-tracking device, you would not be tearing out your hair and screaming in anger. Installing such a device could make you calmer as it would help you to track the location of the car. Of course, in such a scenario, don?t tear off in a rush to heroically rescue your car! Contact the police and let their efficient teams track down the car and give the thief a nasty surprise.
A Basic Understanding of GPS
GPS is the abbreviated form of Global Positioning System. There is a lot of mind-boggling technology involved, including the use of no less than something in outer space: satellites lazily circling our planet. Actually, the satellites are not lazy! They are putting in a lot of hard work. To put it in layman?s terms, a receiver in the mobile phone captures signals from the satellite. These signals are transmitted when the GPS satellite system coordinates the latitude and the longitude points of the receiver. The coordinates themselves are based on what is known as the World Geodetic System 1984 (reference: bestnetcraft.com). The movement and locations of the mobile phone are recorded in the system, and transmitted to the main control system, wherever it is set up.
The System itself can be of 2 kinds: Active or Passive.
An active system is one that literally checks up on the mobile phone all along its route, even noting its speed limits and parking time.
A passive system, on the other hand, merely records the various points of the mobile phone?s route. This information is then downloaded on the mobile phone?s return. This helps, for example, a bakery to keep track of a delivery van?s usage on a daily or a weekly basis. Suppose the driver returns abnormally late from delivering a box of cakes. The owner of the bakery will immediately know, via the downloaded information, whether the driver played truant and went off in a different direction. Detailed questioning of the driver will result in him admitting that he went to a friend?s house to watch a World Cup cricket match!
In short, a GPS mobile phone tracker is a very effective mode of keeping an eye on anything that moves (and even when stationary), no matter how remote the location maybe. Of course, some GPS tracking devices may have restricted range.
What else can a free GPS mobile phone tracker do?
For one thing, it can be a wonderful first aid assistant to you when you are caught in the midst of an emergency. Let?s suppose you are unfortunately the victim of a head-on collision between your bike and an oncoming car. A passing police cruiser comes to your aid immediately. Realizing you require urgent medical attention, the men in blue are instantly able to summon assistance by locating the exact position of the nearest ambulance via their GPS receiver. This speedy response to your dire medical need is what saves your life.
A GPS mobile phone tracker also assists in the quick delivery of documents and parcels via courier mobile phones. That chocolate gift basket you received on your birthday, those flowers you have delivered to your sweetheart on Valentine day, the dozens of pizza boxes that are delivered for your office party, all these, and more, are promptly sent via efficient transport mobile phones equipped with GPS devices. It is the GPS mobile phone tracker that keeps a check on the location of every mobile phone and their routes.
When you wish to go on a trip with your family in your camper, a GPS tracker in the mobile phone will guide you down the right routes via its display screen. On the screen you can obtain precise locations of campsites where you can take a breather. You will also know in advance if the area you are approaching is undergoing major roadwork and the detour you need to take.
The driver of a public bus may need assistance when he has a flat tire. He can immediately contact use the emergency button of the GPS device in the bus to contact the main bus station and request for help. Another bus can be sent to pick up the stranded passengers while the other is being attended to by mechanics.
Some Types of GPS mobile phone Trackers
One sophisticated type of a GPS Satellite Tracker is a device that you can mount in your mobile phone to enable you to monitor its location in any region of the world. It has an external antenna and it can be remotely programmed via special software. You are provided with detailed street maps of various countries, which you can opt to buy separately. The cost could generally be above $1200.
A GPS pocket tracker enables you to monitor the location of your car without the bother of wiring systems. You track the mobile phone easily via your laptop or pocket PC. The cost could be about $200.
EMy car has a GPS Tracking device already installed how do i track the car on the Internet?”
The average GPS receiver does not have a transmitter and will not allow you to track your truck or car so you will need a real GPS tracking device.
Some mobile phone have OnStar which can find the location of your mobile phone and some use car dealers may install tracking device to keep track of their property till it it paid off.
It really depends on what type of tracking device you have purchased. Some GPS tracking device only record where the mobile phone has been and you have to remove the tracking device to retrieve the route information. There are other GPS tracking device that uses GPRS and you can track it almost real time on the Internet, about every 2 minutes or so.
There are also GPS devices that uses both GPRS and WiFi like the DASH navigation system.
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Mobile GPS Tracking