GPS (Global Positioning Systems) have been around for quite some time now. Its first use was with the military, but they have more recently been associated with civilian navigation devices. The latter is the topic of this discussion.
There are three components necessary for the success of a Global Positioning System. Those components are made up of 24 satellites, GPS Receivers, and ground stations. Each component must work in harmony or there will be inaccurate readings. A brief description of each and their functionality follows.
GPS Receivers act just as their name indicates. They receive information from the chosen satellites using radio waves to calculate their exact location. Once this information has been received, feedback is provided to the user. Ground stations have a two-fold operation. The first is to ensure the health of the satellite. The second is to respond to the satellite with its exact location. This location is very important as it is used to later determine the exact coordinates of a GPS device. Satellites determine the coordinates of a GPS device using trilateration. Basically, three satellites use radio signals to determine the total distance from the GPS [http://www.happyjaysgps.com] device. This can become very complicated because of a variety of interference possibilities. Therefore, most civilian GPS systems use additional satellites to increase accuracy.
GPS systems continue to grow in popularity. There is a belief they will one day be as common as the telephone or television. There is also a belief that the high popularity will help to push builders into furthering the technology with improvements much in the same way as the cellular phone in recent years.
By: James D. Allen
Archive for January, 2010
Download Free Maps GPS – Enhancing Your GPS Device With Additional GPS Maps
January 28th, 2010
Several General Positioning System (GPS) maps are already provided with your GPS device when you buy it. Because these maps are offered for free, there is an overhead in getting them. Indeed, these maps do not allow any tweaking in order to meet your specific needs. Another drawback of these built-in maps is their lack of knowledge about your given destination. For instance, let assume you want to travel to Philippines; it is obvious that you will appreciate details about this location beforehand. If your device was purchased in Brazil, you will be very lucky if it has any knowledge about Philippines. Therefore this GPS map cannot act as a travel aid.
Many GPS devices are used as travelling guides for a trip. Therefore GPS devices have superseded our old map artifacts. You may be wondering how useful a GPS device is. It is obvious that having detailed information about your trip in advanced will only make it more enjoyable, faster, safer and reduce any risks during your trip.
Although there are several programs that can be purchased to install new GPS maps on your device, there are also several free programs that can be used for the same purpose. In order to use these, some software prerequisites should be installed at first. These include the cables of your device. You do not to worry about it because they are included with your device when you purchase it.
They are also many websites that can help you to design our own GPS maps. By customizing your maps, you will be able to pinpoint specific locations you are fond of. These include restaurants, bars, night clubs, schools and so forth. You may add traffic reports in your GPS maps in order to avoid traffic jam during your journey.
Another outstanding benefit of GPS systems is their ability to record several maps. For instance, if you are traveling a lot to the same place, your GPS device can save all your personal information once so that the trip you will not be asked to enter your personal details and preferences.
When you have a GPS system, you may find it easier to have many maps about your trips. This will make your trip very enjoyable. You should therefore spend some time looking at pre-installed maps as well as other amazing features of your system.
Briefly speaking, GPS maps offer you the unique opportunity you explore your final destination without heading there. This is very interesting because it is sometimes recommended to glance at a country before formally deciding to go there. Some GPS maps provide outstanding features such as an unlimited online access to view, print, save aerial pictures. Some of them also come with bunch of programs allowing you to personalize them, add texts, graphics, compute GPS coordinates, upload your GPS coordinates and plot them atop of your maps. Updating new GPS maps to your device can be a very daunting experience. There are available in many shopping centers not for free. If you are looking for free stuff, you should definitely look on the internet as several, interesting maps are available.
By: John B Mayall
How Accurate is GPS?
January 27th, 2010
The answer to this question keeps changing along with advancing technology as well as United States law. The first consumer GPS receivers on the market were far less accurate than the receivers available today even though the satellites are the same. Also, before the year 2000, the military intentionally introduced inaccuracies into the civilian GPS signal for “security” reasons. They called this intentional signal error “Selective Availability”. In May of 2000, President Clinton made a decision to turn off SA and allow civilians access to increasingly accurate GPS signals. The military still has the ability to turn off or introduce errors into GPS signals at any time and with no notice but this ability is generally only used for specific reasons of national security.
The best consumer GPS technology available as of 2007 achieves an accuracy level of 15 to 30 feet under normal conditions. Garmin, currently the most popular manufacturer of GPS receivers, claims their GPS units are accurate to within 50 feet 95% of the time. Even within the Garmin GPS receiver line, accuracy specs differ because of the different chips used in the design of different receivers.
GPS Receiver Design Affects GPS Accuracy
If you are looking for the most accurate consumer GPS unit, it’s important to pay attention to the unit’s chip type. The latest technology in GPS receiver chips is the SiRFStar III from SiRF. With this chip in your receiver and WAAS enabled you can expect to reach the best GPS accuracy levels available under current conditions.
Environmental Factors Affect GPS Accuracy
Many different environmental factors can also affect the accuracy of your GPS receiver. Heavy tree cover, tall buildings, deep canyons, and any location in which your view of the sky is limited can affect how accurate your GPS is. Atmospheric conditions can also degrade the accuracy of your GPS unit.
As you can see, there is no easy answer to the question “how accurate is GPS?”. However, you now know the main factors that can affect GPS accuracy.
By: Markus Hamilton
