The Global Positioning System – or GPS – has transformed how the world finds its way. It’s no secret that the popularity of GPS has made it a standard feature in many a car. But in truth there are quite a number of GPS devices that are used in today’s modern society. What began as a government experiment and then a standard device used by the military, is now more popular than ever in civilian society.
When Russia launched Sputnik in the late 1950’s we had our first glimpse into the role that satellites would play in our future. Those who were monitoring Sputnik found that they were able to pinpoint its location based on the radio waves it provided. The seeds of GPS were born.
In the 1960s the U.S. Navy began experimenting with the technology, using the positioning of six satellites to help missile-carrying Navy submarines pinpoint their location. But the Global Positioning System that we know today was designed and implemented by the United States Department of Defense; the first operational satellite was launched in 1978 and by the mid 1990s there were 24 satellites – all of which are still in operation today.
The byproduct of this new technology has been GPS devices, designed to harness the power of satellite navigation to offer the highest level of convenience. It seems as though every year more GPS devices hit the shelves and in so doing they become part of what’s expected in society. The types of GPS devices are varied and your choice to use them depends largely on your frequency of need.
One of the more popular GPS devices is GPS mapping that allows you to visit any number of websites and enter any address in the world. If satellites have access to this area, you are immediately given a satellite picture showing the precise location you requested. For mapping trips, these GPS devices can take information downloaded from your computer and put it to use in your car, giving you detailed directions for the most expedient trip.
Another one of the more popular GPS devices is a GPS navigational unit. These units can either be mounted in your car or come in a portable system that you can transfer from vehicle to vehicle. Once a destination is entered into the GPS navigational system, it can literally walk you through your trip telling you where to turn and the time and distance relative to each portion of the drive. Some navigational units offer a feature whereby you can find restaurants, shopping, hospitals, and accommodations regardless of where you are; this can be incredibly useful when hunting services in a town with which you are unfamiliar.
GPS tracking, another of the GPS devices, allows you to track another person or thing. Many parents use GPS tracking in the cars of their teenage drivers. Others use this system to help protect precious items that are in danger of being stolen.
No matter which of the GPS devices you choose, you will no doubt find GPS to be an essential part of your life before long.
By: Michelle Bery
Posts Tagged ‘Satellites’
What is GPS Used For Today and How Does a GPS Receiver Work?
December 2nd, 2009
When you hear about General Positioning System (GPS) system, you should first consider the GPS receiver. It is the part of the device responsible of processing the signal sent by the satellite in the space to find out your actual location. The receiver is usually placed on the dashboard of your car or underneath it. It renders on a dedicated output device your screen your destination.
The entire GPS is a constellation of about 27 satellites rolling around the center of the Earth at a steady speed. Amongst these satellites, 24 of them are responsible of processing signals emitted by the receiver and the remaining satellites are used for storage purposes on case of an unplanned event. The GPS receiver is responsible of hooking up with satellites used for storage purposes and working out its position from that satellite by computing their distance. The mathematical tenet used for this purpose is named trilateration.
Trilateration can be achieved in two dimensions and also in three dimensions. The rationale of this mathematical principle is to work out a triangle where you are located at the center of it. As soon as the GPS receiver emits its position and makes a connection with other satellites, it immediately works out three nearest points and computes your position.
Three types of GPS receivers can be noticed: those which can be installed in a car, lightweight and mobile GPS receivers and tracking GPS receivers. It is obvious that portable receivers are a huge boon for outdoor activities.
Finally, it is good to know that the actual process of GPS receivers is a little bit more intricate than what was described in previous sections. However, throughout this article, although the main objective was to give a broad overview how they work in theory the next paragraph will delve into advanced details about GPS computations.
From previous sections, we learned that the GPS receiver computes its distance to the nearest available satellites in space by noticing the time spent by the emission of a given signal from the receiver to the satellite. There are another category of GPS receivers that you have not mentioned throughout this article. In order to overcome the lack of precision of the traditional GPS receiver, differential GPS receivers were born. Their rationale is to estimate the level of GPS errors at a stationary receiver station with a location that was already computed before. Since the Differential GPS hardware at the station is already aware of its own location, it can work out its receiver’s level of errors in a straightforward way. The station then broadcasts a radio signal to all Differential GPS-equipped receivers in the nearby area, providing signal correction information for that area. In general, accessing this correction information makes Differential GPS receivers much more correct and precise than traditional GPS receivers.
The most essential function of a GPS receiver is to pick up the transmissions of at least four available satellites and combine the information in those transmissions with information in an electronic almanac, all in order to figure out the receiver’s position on Earth.
By: John B Mayall
