NTP Server Static GPS Antenna Systems
June 24th, 2008 Subscribe To Our Feed
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.
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Dave Evans develops atomic clock time synchronisation systems to ensure accurate time on PC networks. Click here to find out more about GPS NTP Server solutions. GPS Point! Employee Overtime – The employee overtime rate is estimated at about $30 per hour. On average, a company can reduce at least 1 hour of overtime per week with a GPS fleet tracking system.
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Why The GPS Is A Life Saver For Your Boat or Car
June 22nd, 2008 Subscribe To Our Feed
Do you ever get lost? You know, maybe you’re looking for your child’s music recital, and you take a wrong turn and end up in the middle of nowhere. This is a rather common occurrence that happens to the best of us. We all lose our way now and then. However, that doesn’t mean that everyone stops to ask for directions. Some of us hate to stop at the random gas stations or pit stops to get that much-needed input. And this is why we continue to drive around, circling aimlessly. Oh and of course, act like we know what we’re doing. Well, fortunately these days there are simpler ways to deal with this common dilemma. Ever heard of the new car navigation systems? I’m sure everyone has by now. These wonderful little innovations are making life a great deal easier for many of us.
Does your vehicle, van or SUV have one of those car navigation systems? Now, it’s not like the car has to come with one. Although this option is rather choice on some of the newer cars, it can be a tad pricey. The good news is you can buy a GPS system separate and use it whenever, or where ever you like. In fact, Garmin is one of the top sellers of portable and car navigation systems. I purchased one from Best Buy for a few hundred dollars. While this may sound expensive for some, trust me it’s a purchase you’ll be glad you made. Just last summer I had to make a trip to the heartland. Okay, maybe not everyone knows what the heartland is; therefore if you’re not privy to this vital information, the heartland is Iowa. Anyway, I decided to take my nice little GPS system on this trip and it was a life saver. I basically programmed the start and finish point addresses into the navigation system and it told me where to go. And when I say it told me, I mean it literally told me out loud. Many of these contemporary car navigation systems talk to you, which proves wonderful on the road. This way you don’t have to worry about looking down and reading something all the time. Car navigation systems run off a satellite signal and work like a charm any where on the planet.
If you’re in search of a modern GPS system, then it’s imperative to look online. The Internet is loaded with car navigation systems to suit anyone’s needs. Isn’t it time you knew where you were going? Get informed with a new navigation system at your side.
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For more information on the best Car Navigation Systems try visiting Hot Cars Magazine located at http://hot-cars-magazine.com where you will find valuable information on trucks, good car websites and other information.. |
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GPS Technology and Fishing
June 20th, 2008 Subscribe To Our Feed
What type of fisherman are you? Are you satisfied go out and drop your fishing line and be totally unconcerned about if you catch anything or not? Is the time that you spend with your family, friends or even by your self enjoying nature what your trip is really all about? If you don’t caught anything that’s fine-you can always stop at the fish shop on the way home, but it would be nice if you caught something. Or do you feel like your trip’s been ruined because you didn’t caught anything, and go home frustrated. Or is fishing how you make your living, either by catching fish or taking customers out to fish? If you take a customer out to do some deep sea fishing, it would be much better to bring home a happy customer with his catch, who could be possibly a repeat customer or tells his friends about how great his trip was bringing you additional work. A frustrated customer will think twice about using your services again and when planning his next trip, might go elsewhere and may be steering other potential customers away from you. What if there was a way to make sure you go where the fish are? What if there was a way to guarantee that you would catch your limit, to be able to ensure that your customers will go home happy and raving about your great service.
With GPS technology it is now possible to go where the fish are and to remember the spot so you can relocate it. The other good thing about using a GPS while on the water is safety. You can enter the spot where you put your boat in the water in the memory of your GPS unit. Most GPS units hold at least 500 landmarks or areas where you want to get to. If you run into fog or bad weather you should be able to find your way back. Also if you stay out longer than expected you can find your way back in the dark. If you run into an emergency while on the water, you can call someone and let them know your coordinates, and then they could find you. If someone falls overboard a GPS unit can pinpoint the exact area where the incident happened and helping rescue crews with their rescue. This allows you to enjoy your day and not worry about getting back to land safely.
A chart plotter GPS with a map chip can give you your position relative to land features, water depth, and harbor entrances. Using a GPS with a water depth can allow you to follow the bottom looking for fish. It is also possible to let others know about a spot that you have found by using GPS coordinates.
Often people like to fish around a wreck, with a GPS unit you can enter the location of the wrecks to be able to find them easily. Plus knowing where a wreck is only part of the scenario, you need to know how deep that wreck is and if there are any areas you need to avoid. Often a fishing trip starts out before daylight, with a GPS you can pinpoint where you are going.
No matter what your intent is when you go fishing. A GPS can enhance that experience.
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