The Global Positioning System (GPS) is a navigational system consisting of a number of satellites that enables anyone to know their position on Earth. It works regardless of the weather, day or night, using radio signals that bounce between the receiver on Earth and the satellite in space. It is the only fully functional navigation system that can be used anywhere in the world.

Electronics in general has become smaller and smaller, and GPS technology is no exception. Today, you can find many GPS devices which you can hold and operate in the palm of your hand. Most of these handheld devices are designed to be used outdoors such as when you are traveling, hiking or skiing. The GPS unit can not only provide navigational details such as where you are and how to get to where you want to go, but other details such as local and topographic details. Some even provide details on the weather forecast.

Corresponding to the decrease in size has been the decrease in cost. You can find a good quality handheld GPS system at a very affordable price. One small issue with many handheld GPS is the size of their memory due to the need for them to be compact. By spending a little extra, you can usually get a unit which has up to 16MB of memory, and these types are typically more powerful with extra features.

Bikers, hikers, skiers and travelers use handheld GPS units in their activities and there are many devices specifically designed for particular outdoor activities such as biking, golf and hiking. Handheld units are usually very easy to use and have displays that are simple to read. You can even find some GPS units that are voice enabled.

The many different handheld GPS gadgets that on the market today can make it difficult to choose one. Rest assured there are many that will meet your needs. For example, the Garmin StreetPilot 7500 GPS Portable has a 7 inch screen and a wireless remote. It also features maps of US and Canada included, built in antennae, WASS enabled and a MP3 player so you listen to music on the boring parts of your trip.

A palm sized GPS unit is the Garmin eTrex Handheld GPS. The buttons on this gadget are all on the one side to enable you to use it with just one hand and is specifically manufactured to meet the needs of hunters, climbers, hikers and bikers. The software can be updated for free. Another Garmin is the Garmin GPS III Plus which has great reception even in the densest of areas.

A popular Magellan GPS is the Road Mate 2000. Portable, affordable and powerful, it is extremely easy to read the screen with anti-glare and bright features. It also has a battery with a long life.

Buying a handheld unit is very easy. There are many listed in online stores or at your local electronic store. Make sure you do your home work and buy a well know brand that is known for its quality. It is also a good idea to test drive the GPS unit to ensure that you find it easy to use.

Derrick Bogaster
http://www.articlesbase.com/computers-articles/navigate-outdoors-with-a-handheld-gps-unit-500075.html

More than likely there has been a time when you slid in your car and suddenly wondered if you knew how to get where you were going. Well, today with the great automotive GPS systems, you don’t have to worry about this any more. With automotive GPS systems, you can easily get to any destination you may need to go for. There are a variety of excellent automotive GPS systems available today - so how do you pick the best one? Well, here are some top tips that will help you pick out the system that is best for you.

Tip #1 - Figure Out How Often You Need to Use It - First of all, when looking for the best automotive GPS systems, figure out how often you are going to need to use it. If you aren’t going to need it very often, consider one of the inexpensive automotive GPS systems available. Many are very small and plug in to the cigarette lighter in the car. However, on the other hand, if you need to use it often, you’ll want one of the better automotive GPS systems that is user friendly.

Tip #2 - Consider Your Car’s Layout - When trying to choose automotive GPS systems, consider your car’s layout. Many GPS systems have monitors that displays directions and maps on them. Usually the monitors are placed in the dashboard or on an attachable pedestal from the dash. You’ll find in some vehicles, that certain automotive GPS systems can block important vents for air or make it difficult for a person in the passenger seat. So, you want a system that works with the layout of your car.

Tip #3 - Look for Multiple Ways to Get Where You’re Going - Choose automotive GPS systems that allow you to use multiple ways to get where you are going. Many automotive GPS systems allow you to get directions by an address back, an address you type in, a location you select on a map, or even by the nearest intersection.

Tip #4 - Ensure You Get Vocal and Graphic Directions - Having both vocal and graphic directions in automotive GPS systems is definitely a wonderful idea. When choose a system, this is important. It allows you to see where you will be going, but the benefit of the vocal directions is that you don’t have to take your concentration off the road to get the directions you need.

Tip #5 - Find Automotive GPS Systems with Great Features - If you’re shopping for automotive GPS systems, make sure that you find a system with great features. Consider looking for features like Bluetooth, 3D maps, real time updates, or even data on points of interest.

Tip #6 - Keep the Installation Time in Mind - Last of all, if you’re choosing automotive GPS systems, you should keep the installation time in mind. This is especially important if you are on a very tight budget. The longer automotive GPS systems take to install, the more it will cost. So, keep this in mind.

Dennis Frank
http://www.articlesbase.com/computers-articles/automotive-gps-systems-tips-for-selecting-the-best-one-699269.html

The Global positioning System (GPS) is often used by computer equipment, such as NTP Server systems, to provide an accurate timing reference for time critical applications. This article provides an overview of GPS for timing applications and describes the equipment used to install a GPS antenna in a static location.

Overview - Using GPS for Accurate Time

The Global Positioning System is a US military system for worldwide navigation. The system consists of 24 orbiting satellites, each satellite has a highly accurate atomic clock on-board synchronised to UTC time. The satellites continuously broadcast time and position information. The time and position information can be obtained worldwide with a GPS receiver and antenna. GPS works continuously in any whether conditions, anywhere in the world. Additionally, there is no set up fee or subscription charges to utilise the GPS systems. Many computer timing systems and NTP Server systems utilise GPS as an accurate external timing reference.

The Accuracy of GPS Timing Systems

GPS receivers provide highly accurate position and timing information. Typically, a GPS receiver can provide positioning information to an accuracy of 15m. NTP Server systems can obtain timing information from GPS to a resolution of a few nanoseconds.

The GPS Signal

The transmitted GPS signal is very weak low-power radio signal, designated L1 and L2. L1 is the civilian GPS frequency transmitted at 1575.42 MHz. The signals travel by line of sight and can pass through clouds, glass and plastics but are blocked by objects such as metal and brickwork. Therefore, the ideal location for a GPS antenna is on rooftop with a full 360-degree view of the sky. However, often installation on the side of a building or in a window can provide adequate results. As a rule of thumb, the better the view of the sky, the greater the likelihood of a good consistent signal lock.

GPS Timing Antenna Types

The GPS antenna acts as an amplifier to boost the GPS signal for transmission along a cable, usually coax, to the GPS receiver. GPS Timing antenna’s provided with NTP server systems utilise a pole-mounting system. The antenna screws to a threaded pole for installation on rooftops. This arrangement provides the GPS antenna with a rigid mount easily able to withstand high winds without damage. Typically the GPS antenna is fairly small in size, measuring less than 90cm in diameter. Low-cost patch type antennas are also available, but these are generally better suited to vehicle applications.

GPS Antenna Cable Types and Cabling Distances

The cable distance that can be utilised by a GPS antenna depends mainly on the amplification of the GPS antenna and the quality of coax used in the installation. A typical GPS timing antenna may have a gain of 35 db. Relatively low-quality coax such as RG58 has an attenuation of 0.64 db/m at 1575 MHz. Therefore, a cable run of 55m can be obtained using RG58 cable. With very high quality coax cable, such as LMR400, an unaided cable run of 200m can be achieved. However, very high quality coax can be expensive. A good price-performance compromise is LMR200 cable, which can be run unaided to 80m.

Extending Cabling Distance with In-Line GPS Amplifiers

In-line GPS amplifiers provide further amplification of the GPS signal to increase the cable distance between the GPS antenna and receiver. GPS amplifiers are fitted in-line with the antenna cable and obtain power from the receiver via the coax cable. No external power-supplies are required. Typically, a GPS amplifier may add a further 20 dB of gain, adding 30m of low-quality RG58 coax, 40m of LMR200 coax or 100m of high quality LMR400 coax. Additionally, multiple in-line amplifiers may be utilised to further increase cable distance.

Sharing a Single Antenna Between Multiple Receivers - GPS Splitters

GPS splitters allow a single GPS antenna to be utilised by two or more NTP server systems. The GPS splitter splits the signal received from the GPS antenna into multiple outputs for synchronizing multiple NTP servers. GPS splitters are generally available with 2, 4 or 8 outputs.

Protecting GPS Systems - GPS Surge Suppressors

Surge suppressors protect expensive NTP server equipment from electro-static discharges, such as lightning, that may be picked up by an externally mounted GPS antenna. Surge suppressors are installed in-line on the coax cable between the antenna and receiver, ideally where the cable enters the building. Surge suppressors require a low-impedance ground, to discharge any received surge. The surge suppressor requires no power-supply or additional cabling.

David Evans
http://www.articlesbase.com/hardware-articles/ntp-server-static-gps-antenna-systems-95116.html

The Internet has opened up a whole new world for us - bringing places we may never normally see into full view right on our computer screen. Now, like never before, any computer user - regardless of where they are - has instant access to a location that may even be thousands of miles away. Web cams can broadcast live images in a matter of seconds and the Global Positioning System - or GPS - can pinpoint an address down to the street and house through GPS mapping.

GPS is a system of 24 satellites that continually circle the earth. The system as we know it today originally began in the 1960s as the United States Navy implemented a system to help submarines pinpoint their location. The United States Department of Defense - taking this initial work a step forward - designed and implemented GPS. The first satellite was launched in 1978. The 24 satellites of today were not all in operation until well into the 1990’s. Today, we can pinpoint any location based upon the signal of the satellite closest to the location.

GPS mapping was a natural byproduct of such advancements, allowing us to harness the information provided by the satellite system. GPS mapping can find an address and instantly bring you there; some footage is so crystal clear that you can see shrubbery in the front yard and cars in the street.

Specific websites will allow you to simply enter an address or point of reference and information is instantaneously gathered from satellites in space. In a matter of seconds, a photo image appears on our computer screen; it’s almost hard to believe.

Clearly, GPS has brought us into a new world of information; GPS mapping is only part of this process. It’s difficult to know what lies around the corner in the form of satellite information and what role GPS will play in our future. But the possibilities are endless.

Michelle Bery
http://www.articlesbase.com/computers-articles/gps-mapping-a-whole-new-way-of-looking-at-things-93277.html

Technology has achieved many useful developments in satellite navigation systems that allow a small electronic device to navigate its exact location (Longitude, Latitude and Altitude) through satellite. When it knows its position, the navigation device calculates the navigation information including terrain, directions, roads and more.

Nowadays, most vehicles come with the satellite navigation devices pre-installed in them. These devices are generally used by motor vehicle drivers, military, outdoorsmen, boaters and for other military applications.

The well known satellite system that is fully functional at the time of this writing is the GPS or the Global Navigation System. GPS in the United States contains 24 to 27 satellites orbiting at an altitude of approximately 20,000 km with an inclination of 55 degrees in six different planes.

The Russian counterpart to GPS is called the GLONASS, which is derived from GLObal Navigation Satellite System. Though the initial satellites for GLONASS were launched in 1982, the system was not fully operational till 1995. The GLONASS has deteriorated to only 12 satellites, due to economic difficulties. The Russian GLONASS constellation is expected to become fully functional by 2010 and there are plans to include India as well.

The European Union is working on EGNOS derived from European Geostationary Navigation Overlay System. It consists of 3 satellites intending to supplement the GPS and GLONASS systems by determining the accurate signals and position with in 5 meters. It is expected to function in 2006.

The European Space Agency is working on introducing an alternative to GPS, called Galileo. The receivers will be able to combine the signals of 30 Galileo satellites and 28 GPS satellites to get highly accurate positions.

There are many satellite navigation systems yet to launch in several countries. The Satellite system of France is called the DORIS (Doppler Orbitography and Radio-positioning Integrated by Satellite) The Chinese system is called BEIDOU, but these satellite systems do not come under the caliber of GPS, GLONASS and Galileo.

James Dyson
http://www.articlesbase.com/advertising-articles/gps-navigation-systems-what-next-60709.html