Using GPS to Synchronise Computer Systems

Categories: GPS Articles | February 23rd, 2009 | by Mike Tucker | no comments

The Global Positioning System (GPS) is a US military system intended for global navigation and positioning. GPS is a satellite based system that consists of 24 earth orbiting satellites, each transmitting a weak radio signal that can be used to provide accurate positioning information anywhere on the globe. Each satellite has an integrated synchronised highly accurate atomic clock that can be utilised by ground based timing and synchronisation equipment.

This article describes how the GPS system can be used to provide an accurate time and frequency reference for NTP servers and computer network time synchronisation.

GPS timing information is continuously broadcast by each GPS satellite. GPS time is not affected by leap seconds. Therefore, GPS time is currently about 14 seconds ahead of UTC time. However, offset information is available to readily convert GPS time to UTC time, which is used in NTP server and computer time server systems.

Each GPS satellite transmits information as very low-power radio frequency transmission. Two frequencies are used, one for civilian use coded L1, and one for military use coded L2. The civilian L1 frequency is the most widely used and is transmitted at 1575 MHz. The GPS radio transmissions can easily pass through plastic, glass and clouds but is blocked by metal and brick structures.

An antenna is utilised to boost the GPS signal and pass the signal along a coax cable. For consistent operation a GPS antenna needs to have a view of the sky. Ideally, it should be located outdoors on a rooftop with a good 360-degree un-obscured view of the sky.

GPS antennas are very sensitive to cable types and distances. The maximum cable length that a GPS antenna can utilise depends on the quality of coax utilised and the gain of the GPS antenna. Higher quality coax cable generally have much lower attenuation figures and hence provide much longer cable runs between the receiver and antenna. Typically, a low-quality coax can run to 20-30m, while a high quality coax can be used in excess of 100m cable runs. To increase these distances still further, a GPS amplifier can be used to amplify and boost the received GPS signal.

GPS timing systems also utilise a GPS receiver in order to decode the received GPS transmission and convert it to a computer readable format. The receiver decodes the GPS time and positioning information and converts it into a regular serial transmission that can easily be read. GPS NTP servers and computer time servers may also utilise a precise pulse per second output generated by the GPS receiver to provide ultra-precise timing. The timing pulse output can typically provide synchronisation down to a few hundred nanoseconds.

To summarise, the GPS system is ideal for synchronising NTP server and computer time servers. Accuracies of a few hundred nanoseconds can be reasonably achieved with low-cost GPS receiving equipment.

David Evans is a technical author with many years experience in the time and frequency industry. David has written a number of technical articles providing information on NTP servers. For more information on computer time server systems, please visit: http://www.timetools.co.uk/data/time-server.htm

Article Source: Using GPS to Synchronise Computer Systems - ArticleSpan.com

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Use Motorcycle GPS To Turn An Ordinary Ride Into A Pleasure

Categories: GPS Articles | February 20th, 2009 | by Mike Tucker | no comments

Ever been on one of those motorcycle trips that turn into a disaster? You know the ones, it never stops raining, you get lost, and you never get to where you wanted to go because it all got too hard.

A good motorcycle GPS system can turn a disaster into a triumph. It won't stop it raining, they aren't that good, but it should ensure that you get to where you want to go with the minimum of problems via the best route.

Modern GPS is an extremely valuable tool to make navigating a snap. In the past it wasn't totally user friendly for the inexperienced user, giving limited information relating to your position on the planet, and not a lot more. Extremely useful for some, like those in the military, but of limited value for most of us who want a simple efficient and reliable navigation system.

However in the last few years all that has changed and GPS navigation is now a reliable, extremely user friendly and relatively cheap navigation solution for anyone, including bike riders.

Modern satellite GPS navigation systems, for motorcycles, cars, walkers or anyone else who needs one, are extremely good. They are relatively inexpensive considering how useful they are. And now with satellite GPS technology combined with modern mapping software they provide a total navigation solution unlike anything ever seen before.

You can plan your ride before you start it, put the details in your GPS unit and it will plan the entire route for you, and tell you how to get there as you travel, both by screen display and voice prompts direct to your earpiece in your helmet via modern bluetooth technology. Download it all at the end to keep for next time or share with your friends.

With a little time anyone can learn how to use a motorcycle GPS unit and with some practice will be adding a whole new dimension to their rides, particularly the long rides. And you also get all sorts of extras with a modern dedicated motorcycle GPS system that make life a little easier when you're out on your bike, like the ability to load your favorite music to listen to on the ride, or to display your photos to your friends as you go, or to have up to date real time traffic information so that your GPS can direct you around traffic jams, reselect a new route and save you time, fuel and frustration.
And lots lots more.

In the past riders had to make do with GPS units that were not designed for motorcycle use. They were often intended as hand held or auto GPS systems, and lacked many of the features that are essential to operation on a bike that is used outdoors with the display on the handlebars in the weather, and suffering from all the vibrations that are an integral part of motorcycle use, especially offroad.

But there are now dedicated GPS motorcycle systems that are specifically designed for motorbike riders. They offer the sorts of features that are much more important to bike riders than to other users. These include such things as a display that is easier to read in the sun or rain, waterproofing ability and vibration resistance. None of these are important to, say, a driver of a car, but are extremely important to a motorcycle rider.

The waterproofing of these GPS units for example is tested to exacting standards, and they are designed to be used with a dedicated mount that itself has been designed to minimize vibration problems.

Companies well known in the field of GPS design like Garmin or Tom Tom make motorcycle GPS systems that offer all those benefits discussed, and more, and make extremely high quality units that are now in use on many many bikes around the globe.

Systems like the Garmin Zumo or the Tom Tom Rider are both superlative motorcycle GPS systems and if you shop online you can buy these new for well under $1000.

So if you've suffered a motorcycle disaster trip, and you'd like to find a way to avoid another one in the future, consider a good motorcycle GPS system. They make motorcycle navigation easy and fun. You'll never regret it.

For a website totally devoted to Motorcycle GPS visit Peter's Website Hot Motorcycle GPS Deals and find out about Motorcycle GPS systems as well as Garmin Motorcycle GPS systems and more, including Tom Tom Rider navigation systems and find some hot motorcycle GPS videos.

Article Source: Use Motorcycle GPS To Turn An Ordinary Ride Into A Pleasure - ArticleSpan.com

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GPS Tracking Equipment - An Overview of the GPS Live Vehicle Tracking Equipment

Categories: GPS Articles | February 19th, 2009 | by Mike Tucker | no comments

The GPS live vehicle tracking equipment is just an outstanding state-of-the-art electronic equipment. By making use of signals from satellites in the space, with the advent of the General Positioning Satellite (GPS), it is now possible to know the position, direction and speed of any car in real time with the GPS live car tracking tool.

The GPS live vehicle tracking tool is a tiny electronic tool to be put wherever within a car, even though many people prefer to put it underneath the carriage, aiming at hinting to the driver the actual position, direction and speed of the car in the space. Depending on its actual purpose, the GPS tracking vehicle in real time device can be installed in either the engine or in front of the driver. In the case it is used as a navigation aid, it could be placed in a magnetic box and the setup process is quite straightforward and quick. The driver will not even be aware of it. This opportunity thus made the GPS vehicle tracking in real time a good candidate of private investigation. This device can also be used for many purposes. For instance, it could be used to spy cheating wives at night, it could also be used to track teenagers’ cars when there are not experienced and responsible enough to drive their vehicles. Other applications of this device can be noticed by a serious need to deter car thieves and truck companies wishing to track the routes of a fleet of trucks in order to improve their delivery times. An employer also can make use of this device to make sure that his employees are not abusing company car privileges.

Having learned in depth its applications, it is now time to delve into his operational mode. First of all, it should be noted that the device is offered with a program already setup in a dedicated personal computer. Secondly, it sends signals to satellites present in the space. These satellites are used for multiple purposes such as TVs, internet, weather forecasts and tracking objects in the space. After transmitting the signals to the available satellite, this satellite in turns replies by sending another signal which is then interpreted by the software of the device installed on the other computer. Therefore the computer user can actually render its position in real-time.

With such information, it is straightforward to know the actual position, direction and speed of a given car. Some tools even go further by giving a history of previous positions and also offering you the wonderful opportunity to even watch the driver. This is important for some parents who are concerned of the safety driving of their children.

Important uses of the GPS live vehicle tracking equipment include law enforcement and deterring vehicle thieves. Furthermore, this tool is extensively used for police investigation. The same device can be used for other purposes such as spying a cheating wife and making sure that an employee is not abusing his company car privileges. With all these applications, it is reasonable to admit that the GPS live vehicle tracking is an amazing technology.

You can learn more about gps navigation rating system and get access to download free gps software only at http://www.gpsportabletracking.com, the internet's most popular GPS auto tracker site

Article Source: GPS Tracking Equipment - An Overview of the GPS Live Vehicle Tracking Equipment - ArticleSpan.com

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