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Wednesday, August 12, 2009

Cheap GPS Systems For Popular Brands


There are plenty of GPS units developed by top manufacturers that have been in the industry for years. Many of their latest products are geared towards ordinary drivers and not just frequent travelers alone. Because of the convenience and safety that GPS systems provide to drivers, cheap GPS systems had to be developed as well to convince ordinary drivers to give these devices a spin.

Competition is very heavy now amongst these makers, but that is good news for everyone because all the popular brands have their respective cheap GPS systems. There is no best brand at the moment as some people judge a GPS by its user interface and all of the popular brands have good interfaces for their GPS units in their own unique ways. To ensure that you get any of the cheap GPS systems, refer to the reference below sorted by manufacturer.

Garmin

Garmin nuvi devices are highly recognized for their friendly user interface and easy setup process. The cheap GPS systems offered by Garmin are the Garmi nuvi 205 series which are a bit dated and the newly introduced 1200 series which has the same features as the 205 series, but are much thinner and do not see a huge price increase. These are the best GPS devices to get for first-time GPS users that want a fast an accurate GPS navigator. They also have loads of points of interests compared to the rest of the brands.

Lowrance

Lowrance devices are also innovating and spending much time making their cheap GPS systems even better drivers and even road warriors. Lowrance GPS units are just as good as their mainstream Lowrance counterparts in terms of features. They perform amazingly well and these devices are easy to start up and a have a simple interface to make route planning easy for beginners whether traveling in a car or on foot.

Magellan

When it comes to cheap GPS systems manufactured by Magellan, go for the RoadMate series because these devices omit all the bells and whistles found in the Maestro and concentrate on route planning and driving convenience. Many of their budget models have text-to-speech capabilities just like the other brands and have decent performance. Their user interface is also pretty good with the QuickSpell feature that is common amongst their units to assist people in finding their destination faster.

Each manufacturer has cheap GPS systems with different advantages. What they have in common is that they are all inexpensive and easy to use. The final choice should depend on the desired technologies and overall performance.

The accuracy and assistance that a GPS unit can provide to both travelers and outdoor enthusiasts alike will ensure individuals that they will never be lost or lose precious time in getting from one point to another. Cheap GPS systems whether for auto, or handheld units for the great outdoors or sports such as golf, or even marine GPS units give you the ability to know your surroundings at all times. Fitness GPS units are also extremely popular for there ability to be able to perform a myriad of tasks for health minded folks and athletes alike. With functions that can measure speed, distance, pace and calories burned for walking or running and much more depending on the model chosen. GPS units are an affordable device that can assist people and travelers in a multitude of amazingly accurate ways.

By David Neargardner

Thursday, July 16, 2009

Child GPS Locators

Why Do We Need A Child GPS Locater?

There is no question that our world does change almost daily. We are becoming almost too familiar with all the terrible act's of violence, crime's and abuse. Its sad, even though crime's of this nature have plagued our society, and human kind as a whole, there is no denying that the sheer volume seem's to be increasing yearly. And as parent's we definitely have thought about how horrible it would be to lose a child to some deranged kidnapper, or anyone else that could commit serious crimes. We have, undoubtedly, ran through the various situation's, the fear of being powerless once our child has "disappeared", and the absolute devastation and emotional destruction that occurs once a child has been a victim of such crime's.

Of course we try to be as careful as humanly possible. Thinking of and developing safety precautions, like the cell phone, or the exact word's to scream if anything was to happen. But inevitably , somehow we must come to term's with the real lack of control we are faced with in the larger scheme of thing's. As a parent, I can tell you that I have thought of everything when it come's to ensuring my child is never left in harm's way, or left alone. But too many time's I find us in situation's that could be ultimately be dangerous, if a criminal was to decide to cause harm to my child.

The bottom line is, we cannot always protect our children.

Sometimes We Are Not In A Protective Position
Please forgive me if you think we can. But our children reach a certain age where we must give them a certain level of freedom. Whether it be letting them play with friends, or walk to school, or even play in the yard. But the big problem with the age at which our children first begin there minor independence, is that they are still so young in term's of protection and really comprehending the severity of our worlds situation. And even though we do our best to present our children with the knowledge and the truth about being careful, we still cannot completely ensure their safety.

That's why using a Child GPS Tracking Device should definitely be discussed between parent's. There is know better feeling than knowing exactly where your child is whenever you want. Think about looking at your Cell Phone or PC and seeing the EXACT location of your son or daughter. Its amazing. I feel a strong wave of warmth come across me just from thinking about it. I have found that using a Child GPS tracking device also let's us do a terrific job of parenting as well.

Check Out The Child Locator GPS

Here are some great Benefits of the Child GPS Device:

* The Device is small enough to for the child to conceal it and keep from losing it
* Know the exact location of your children Instantly
* Build trust with your child and the wil learn to be honest about there where abouts
* Always know that your children make it to school
* If they get lost you can easily give then accurate directions
* The Amber Alert GPS Device is completely silent
* The GPS Device is even great for Mall's and stores
* Feel safe and secure when at amusement parks
* These GPS Children devices are great for vehicle's and other personal items as well
* And tons more - There are no limits to what you can us these Child Location Devices for.

You know ,one of my favorite thing's about these tracking device's is the fact that I feel like I am truly doing all I can do as a Dad to protect my children. Just knowing that I will never look back and wonder if there was more I could have done. But I also feel like my parenting has improved. When my children are with friend's at the movies or at a friends house, I can just check out the location, and when I can see that they are there, I really don't have to keep calling them or make them call me.

The GPS Tracking Device has actually IMPROVED our parent-child relationship!

That is so amazing in so many different way's. We all know that no parent-child relationship can be perfect, but what a huge breakthrough this GPS device has been.

By Joshua Mintz

The Best GPS For the Money


The best GPS for the money (automotive GPS) will usually be found in a clearance model once the model has been discontinued by the manufacturer. Recently, the chip sets that makes GPS units function have not been significantly updated and the discontinued units still perform very well. If you don't need the latest and greatest, you can find a really good buy.

When you are looking for the best GPS for the money, always look for a unit that speaks street names. The prices on these discontinued units will be low enough that you do not want to buy a unit that does not speak street names. Taking your eyes off the road to read the street name on the GPS display is extremely dangerous. Do not compromise on this feature!

Other features to look for in the best GPS for the money are screen size, MP3 player, Bluetooth, and free shipping.
For many months, the Garmin Nuvi 350 was the best GPS for the money. Its price dipped down to $160.00 in January 2009. It was loaded with features for the $160 price with standard screen size, MP3 player, picture viewer, (no Bluetooth). However, at the time of the writing of this article its price has risen to over $345 USD so forget it.

In April 2009, the best GPS for the money was the Garmin Nuvi 360. This unit has been discontinued by Garmin, but it was selling for the incredibly low price of under $150 on Amazon. It has a standard screen (2.8 x 2.1 inches), MP3 player, picture viewer, and Bluetooth.

The key point to take away from this article is there is always a best GPS for the money. You just have to know how to find it. This best GPS for the money will change periodically as manufactures compete and as GPS units are discontinued and the stores clear the discontinued inventory.

You can find the best GPS for the money on the-best-GPS.com. It contains instructions with pictures that show how to use Amazon.com as your research tool to find the best GPS for the money.

Be a smart shopper, save a bundle, and learn how to buy the best GPS for the money.

By John V. W.

Portable GPS Handheld Devices - Defining Waypoints, Routes and Tracks


Handheld GPS devices are becoming more and more popular for walking and hiking enthusiasts everywhere. With so many models available on the market today offering so many various features, it's easy to become overwhelmed and confused about what you need, and what some of the features even mean.

Two basic questions that many people about using handheld GPS devices are "what are waypoints?" and "what is the distinction between routes and tracks?". Here is a simple explanation that should give you a good understanding of these terms.

Waypoints are precise geographic locations defined by longitude and latitude. Waypoints can be recorded by your GPS unit by pressing the waypoint record button. Inexpensive portable GPS models have limited capacity and will keep relatively few waypoints; top models can store hundreds of waypoints, and you can even give them names and manage them within your GPS.
A route is a set of waypoints connected by straight-line that guides you where you want to go. You "tell" your GPS unit that you want to navigate from one waypoint to the next, and your GPS shows you the route by drawing a straight line between waypoints. This means your GPS will not tell you there is a bend ahead in trail; it will just guide you in a straight line to your next trail junction or campsite. (Keep in mind, that for automobile navigation, the term "route" has a slightly different meaning.)

A track is a record, created by your GPS, of where you have been. As you go on your hiking expedition, your GPS device records track points and displays what many people describe as a "breadcrumb trail". The track represents the road, trail, path, etc. that you followed. Curves are formed with short line segments, so the shape of the trail you have taken is more accurate than the straight-line segments representing a route. Tracks lets you easily go back to your starting point.

Some portable GPS models also let you download your track to your computer to create a record of your trip and print it if you wish. As in the case of waypoints, low-end GPS models offer limited track point storage, while high-end models can store thousands of track points.

By Patricia Peters

How Were GPS Systems Developed?


GPS Navigation Systems technology was originally developed by the United States Department of Defense and was meant for military use to keep track of enemies and know their position at all times. Tracking technology has been around for quite some time actually - since World War II to be exact.

Navigator GPS design is based partly on ground-based radio navigation systems developed in the early 1940's that were used in World War II. These systems were named LORAN and Decca Navigator and were focused on knowing where the enemy was so they could either attack or retreat depending on the size of the forces.

Additional inspiration for modern day GPS systems and GPS handhelds came when Sputnik was launched by the Soviet Union in 1957. A team of scientists monitored Sputnik's radio transmissions and discovered that because of the Doppler Effect, the frequency of the signal being transmitted was high as the satellite approached and lower as it moved away. The Doppler Effect is the change in frequency and wave length of a wave as it is perceived by an observer moving relative to the source of the waves.
This team of scientists that was observing Sputnik's radio transmissions soon realized that since they knew their exact location on the globe, they could pin point where the satellite was along its orbit by measuring the Doppler distortion. This was groundbreaking and very exciting for the military at the time. This technology is used in radar laser detectors too.

The United States Navy used the first satellite navigation system called Transit. It was first successfully test in 1960 and was quite mind-boggling for everyone in the military. When the Navy tested Transit, they did so hoping for some quite specific results. Using a constellation of five satellites, they found that the system could provide a navigational fix approximately once per hour. Today's GPS navigation systems like the Garmin Nuvi GPS use as many as twelve satellites to lock on for instant positioning fixes.

In 1967, the Navy developed the Timation satellite which proved the ability to place accurate clocks in space. This is a technology that the GPS navigation system relies on. In the 1970's, the ground-based Omega Navigation System, based on signal phase comparison, became the first world-wide radio navigation system. This was the foundation and building block of today's GPS Portables.

In February of 1978, the first experimental Block-I GPS satellite was launched into space and the development of modern-day GPS systems began. These original satellites were initially made by Rockwell International. Now, the satellites we use for GPS are manufactured by Lockheed Martin.

In 1983, Soviet interceptor aircraft shot down a civilian airliner flight KAL 007 as it flew in restricted Soviet airspace. This heinous act killed all 269 people on board - all of whom were civilians. Shortly thereafter, President Ronald Reagan announced that the GPS system would be made available for civilian use once it was completed. Because of this horrible act on the part of the Soviets, developed of the GPS navigation system was stepped up more than it ever had been before and experimentations began in earnest.

By 1985, ten more experimental Block-I satellites had been launched into space to validate the concept of GPS and in 1989; the first modern Block-II satellite was launched. By December of 1993, the GPS system achieve initial operational capability and just a month later, a complete constellation of 24 satellites were in orbit with full operational capability declared by NAVSTAR in April of 1995.

A year after that, President Bill Clinton realized the importance of GPS to civilian users as well as military users which prompted him to issue a policy directive that declared GPS to be a dual-use system meaning civilian as well as military. He established an Interagency GPS Executive Board that was responsible for managing GPS as an asset of the United States. With this came the commercial brands such as Garmin Nuvi GPS.

Plans began in earnest to improve upon the system for the everyday user of the navigation system. An announcement was made that the government was going to upgrade the GPS system with two new civilian signals that would lead towards enhanced user accuracy and reliability particularly with respect to aviation safety. Also, GPS handhelds would be made.

Since those early years, the GPS technology has evolved into something that the everyday public uses and uses with amazing accuracy and reliability. What began as a way to keep track of our enemies is now used to help guide us along the way during trips and excursions. Such companies as TomTom, Magellan and Garmin Nuvi GPS have made a business out of this.

In fact, the GPS system we have today has many applications including map making, land surveying, and commerce uses. Plus, because of the way a GPS can pinpoint times with amazing accuracy, scientists are able to use it in many applications including the study of earthquakes and the synchronization of telecommunications networks. Who knew that golfers would be able to use a GPS handheld to determine the distance to the flag.

New uses for GPS systems are constantly being discovered and the way that technology is always evolving, we are sure that even more new uses will come about for the GPS systems. They will probably always be finding new uses too as the system is constantly improved upon. Next time your on the highway, safely look over at the car next to you and see if it might contain a Garmin Nuvi GPS.

By Richard Alexander

Saturday, July 11, 2009

GPS Navigation Systems Have Come a Long Way

Gps systems have come a long way since they were first designed for the US military. The first signal from NAVSTAR 1 was received on Feb. 22, 1978. NAVSTAR 1 was launched from Vandenberg Air Force Base in California and was the first of 24 satellites that make up the Global Positioning System (GPS). The first generation of satellites that make up the Global Positioning Systems 24 satellites were launched between Feb. 22, 1978 and Oct. 9, 1985. Since it First became operational the Global Positioning Systems has revolutionized the way America goes to war and provides a GPS system in which the world relies on for precise navigation.

The Global Positioning System's constellation of orbiting satellites is managed by the United States Air Force 50th Space Wing. The unit is the host wing at Schriever Air Force Base, located in east Colorado Springs, Colorado. They are responsible for tracking and maintaining the command and control, warning, navigational, and communications satellites for Air Force Space Command as well as the Global Positioning System satellites. Full Operational Capability was declared by NAVSTAR in April 1995 (NAVSTAR is an acronym for NAVigation Satellite Timing and Ranging, and is the official U.S. Government name given to the GPS satellite system).

The US government granted the Global Positioning System available for civilian use in the late 1980s and with no subscription fees or setup charges to use the GPS system the civilian GPS market exploded, especially in the last decade. A new generation of sophisticated GPS satellites are replacing the older satellites and there are now 34 GPS satellites in orbit that provide combat capability for military applications and aircraft navigation aids. Civilian applications include ATMs, bank and stock market transactions as well as power grid management. Currently 31 of the 34 GPS satellites in orbit transmit navigation and timing signals to civilian and military users around the world.

Gps for civilian use

The civilian GPS system wasn't always as it is today and the US military is still keeping the most accurate Global Positioning Systems available classified for national security. But GPS upgrades for two new civilian signals to enhanced user accuracy and reliability, particularly with respect to aviation safety were planned in 1998. Then on May 2, 2000 "Selective Availability" was discontinued as a result of the 1996 executive order, allowing users to receive a non-degraded GPS signal globally, and in 2004 QUALCOMM announced the successful tests of assisted GPS for mobile phones that led the way for the GPS aided cell phones that are widely used today.

In 2005, the first third generation GPS satellite was launched and began transmitting a second civilian signal for enhanced user performance. Then in September of 2007 the Air Force completed a four-phase transition of the Global Positioning Systems ground segment to it's new Architecture Evolution Plan. The ground segment's provide command and control of the satellites and generates the navigation message for satellites to broadcast to the users GPS device to calculate their earth's position. The new Gps satellites include new high-powered, anti-jam military-code, along with other accuracy, reliability, and data integrity improvements for both civil and military users. This modernized version of the world's greatest free utility was designed to ensure the US has the most precise and secure positioning, navigation and timing capability through 2030.

Europe and Russia develop their own GPS

In 2004 the United States signed an agreement with the European Community establishing cooperation with Europe's planned Galileo system. Galileo is a global navigation satellite system (GNSS) that is currently being built by the European Union and is separate from but complimentary to the United States Global Positioning System. The European Union's Galileo system should be operational by 2013. The European Community's political aim is to provide an independent GPS system that the European nations can rely on in times of war or political disagreement, because both Russia or the USA could disable use of their national systems by others (through encryption).

The Russian GPS system GLONASS is a radio-based satellite navigation system that was developed by the former Soviet Union and now operated for the Russian government by the Russian Space Forces. Like the European GPS system the Russian GPS system also functions separate from but is complimentary to the United States Global Positioning System. Russia began launching satellites for their GPS system into space on October 12, 1982 and was completed in 1995. The system rapidly fell into disrepair fallowing the collapse of the Russian economy but in 2001 the Russian government began restoring the system with hopes of restoring global coverage by the end of 2009.

GPS Systems today

Depending on the GPS unit a GPS receiver only needs a signal from 3-4 satellites to calculate the units position and will work in any weather conditions, anywhere in the world, 24 hours a day. There are no subscription fees or set up fees like with a cell phone to operate GPS receivers and although some GPS receivers have extra features like real time traffic updates that will have a monthly charge, some GPS receivers like Garmins Nuvi "T" series come with free live traffic for the life of the unit. Today's GPS is extremely accurate thanks to their parallel multi-channel design. Garmin's 12 parallel channel receivers are very quick to lock onto satellites when first turned on and they maintain a strong lock even in dense foliage or city's with tall buildings because they continuously track signals from up to 12 satellites at any given time. Even if a 12 parallel channel GPS receiver loses signals from 8 satellites at once it will still function properly.

WAAS (Wide Area Augmentation System) was developed by the Federal Aviation Administration to augment the Global Positioning System to improve its accuracy, integrity, and availability. WAAS was originally intended to enable aircraft to rely on GPS for all phases of flight, including the precision approach to airport's within its coverage area. All though originally intended for aviation most GPS receivers today are WAAS-enabled including automotive, boating chartplotters and hand-held units. WAAS uses a network of ground based reference stations, in North America and Hawaii, to measure small variations in the GPS satellites' signals.

Measurements from these reference stations are routed to master stations and then they send correction messages to geostationary WAAS satellites. Those satellites then broadcast the correction messages back to Earth, where WAAS-enabled GPS receivers use the correction data while computing their positions to improve accuracy. WAAS enabled GPS receivers are accurate to within 3 meters and that make them the most accurate GPS receivers for civilian use on the market today. In fact a WAAS-enabled GPS receiver can even give you directions right down to the lane your car is traveling in (as long as the mapping program supports "lane assist" directions) and With no additional equipment or fees required to take advantage of WAAS-enabled GPS receivers they are becoming as common as cell phone's.

By Jeff Sanders

GPS Navigation - Finding Your Way Through the Product Maze

The range of options and variety of brands and models can make choosing a GPS system a little confusing. Price is an obvious consideration but so are the built in features and available options, how and where you intend to use your GPS and what kind of directional assistance would be most helpful for your particular needs. When deciding which GPS product is right for you, considering the answers to some of the following questions will help you navigate through the maze of available products and find the right one for your needs.

- Are you looking for basic GPS navigation for you car to help get you around town or something with a few more features that would be helpful on trips?

- Are you looking for a GPS system with more versatility? Perhaps a unit that could be used in a car and/or outdoors hiking, biking or sightseeing?

- Are you looking for a feature packed system that provides spoken navigation and a variety of additional information, traffic and weather, compatibility with Bluetooth devices XM radio and more?

- Are you looking for activity specific GPS capabilities for use during hunting, fishing/marine use, or fitness training?

The following information is offered as a guide to assist you in determining which product is right for you. It is not a review of any specific brand or model. The brands mentioned are only used as examples of the kind of GPS being discussed. Keep in mind as you consider your needs that many GPS systems designed for use in a car can easily be carried in a pocket, purse or pack and used to navigate on foot. And likewise, many handheld products can be mounted in a car, boat, ATV or on a bicycle and when installed with street map software, can be used to navigate on streets and highways.

GPS products with basic capabilities will be able, literally, to get you from point A to point B by utilizing one or more saved "Way points". These type devices do not offer mapping capability. You can think of way points as pebbles left behind you as you make your way. To return, you move back along your route, collecting the pebbles you left to mark the way. Basic models function in much this way, dropping the "pebbles" for you and pointing the way back to them to lead you home. Examples for use of this type GPS might be saving the location of your parked car at a crowded shopping mall or sports facility when you arrive so you could easily find your way back when you are ready to leave. Or instead of a parked car you might save the location of your campsite and points of interest along a hike and then easily navigate back at the end of the day. Examples of these types of handheld GPS units would include:

- Bushnell's Backtracker Personal Location Finder

- Garmin eTrex H

- Garmin Foretrex 101 and 201

- Geko 201

- Garmin GPS 60, 72, and 76

Basic automobile GPS navigation requires a bit more sophistication than seen in the previously mentioned handhelds. These products offer pre-loaded maps, color screens, and greater memory capacity and are the types of products you would want to consider for use in a vehicle or for back country hiking, hunting or fishing. Beginning level examples of these products would be:

- Garmin Nuvi 200, 205, 205W

- Magellan Roadmate 1200, 1400,

- Magellan Maestro 3200 series

Moving up a notch consider products like the following handheld units for outdoor activities :

- Garmin eTrex Legend, Venture HC, Vista,

- Garmin GPSMAP 60

- Magellan Triton 200

Moving up to the mid-level you may want to consider products like these for your car:

- Garmin Nuvi 250, 255, 260, 265, 270 series

- Magellan 1412

- Navigon 2000S

And for outdoor handhelds:

- Garmin eTrex Summit HC, Vista HCx, GPSMAP 76S

- Bushnell ONIX200

- Magellan Triton 300

- DeLorme PN-20

Moving up to more advanced products does not mean struggling with products that are difficult to use. Features such as touch screens and spoken turn by turn directions make these automobile GPS products very easy to use. Advanced products provide a greater number of features and a higher level of functionality and versatility. Options such as XM radio, Traffic updates, or other services are included or can be added with some of the more advanced models. Some of these options require the purchase of monthly subscriptions. Examples of these products for your vehicle would be:

- Garmin Nuvi 265WT, 275T, 500, 550, 750, 755T, 760, 765T, 775T, 780, 785T, 855

885T, 5000

- Garmin Zumo 550

- Garmin Streetpilot 7200

- Magellan Maestro series

- Navigon 2200T, 2100MAX, 7200T, 8100T

Advanced handheld GPS models generally offer more internal memory or the ability to add mapping and other content using data storage cards. Mapping data can be downloaded to the card and the card plugged into the device. In this way one device can be used to navigate city streets, inland lakes or coastal areas, or trails in a national park depending on the mapping software installed. These types of handhelds include:

- Garmin Oregon and Colorado series

- Garmin GPSMAP 60Cx, 60CSx, 76Cx, 76 CSx

- Magellan Triton 1500, 2000

- Bushnell ONIX350, ONIX400

- DeLorme PN-40

There is a group of advanced products which should be mentioned separately because they not only offer excellent automobile navigation features but can be used for marine GPS navigation on the water or on a trail as well. These GPS models are referred to as crossover or hybrid GPS units and include the following examples:

- Garmin Nuvi 500, 550

- Garmin GPSMAP 276C, 478C, 620, 640

- Lowrance XOG

Another group of handheld GPS is designed with a specific use or feature in mind. Some specialized handheld models provide basic GPS navigation but are also coupled with enhanced specialized functionality. Others do not offer GPS navigation but use GPS technology to gather data used in activities such as fitness or sports training. Examples include:

- Garmin Astro - Handheld GPS that can also be used to track hunting dogs.

- Garmin Rino - Handheld GPS with 2-way radio capability.

- Timex Ironman - GPS worn on the wrist. Tracks such things as time and distance for running, biking, and swimming fitness training.

- Garmin Edge, Forerunner, and Foretrex - Edge is a Personal Training/Biking calculator using GPS for fitness training. Forerunner and Foretrex are other examples of wrist mounted GPS, Forerunner for fitness training and Foretrex offering basic way point GPS navigation.

This has not been an all encompassing discussion of GPS products but I hope this information will help you understand the differences between some of the more popular models when choosing which is the right GPS for you.

By James E McMillan

Thursday, July 2, 2009

NTP Server Static GPS Antenna Systems


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.

By Dave Evans

Sunday, June 21, 2009

Tom Tom GPS Navigator Will Get You Where You Want to Go


Tom Tom is a leader in the field of GPS technology and they have brought many useful and innovative products onto the market including portable GPS units, GPS for iPhone, and Bluetooth GPS devices.

Tom Tom GPS navigator is available in several types of car navigation systems. They can be built-in or portable. The higher end units have many handy features like voice command and control, advance lane guidance, map sharing, IQ routes for picking the best route based on conditions and hands free calling using speech to text technology. This GPS device can even tell you where to find the cheapest gas.

All units have map sharing technology which means you or anyone else can update a map and it is instantly updated for everyone else using the map. This helps to ensure that you have the very latest information regarding road closures and route changes.

When you have a GPS navigator you don't have to worry about getting lost or wonder when the next gas station will pop up either. These units provide you with turn by turn directions for where ever you want to go. Not only that, it will keep you updated on changes in traffic flow and issue safety alerts. Tom Tom will let you know where the nearest gas station or restaurant is located and is also integrated with Google's local search.

If you travel by bike or motorcycle instead of car you can still take a GPS device with you. They has developed specialized navigators that mount on two wheeled vehicles. They are just as sophisticated as the car units and have a sensitive touch screen that can be manipulated while wearing biking gloves.

They even offer devices for your smartphone, iPhone, and Bluetooth device. The Bluetooth GPS offers crystal clear spoken directions as well as 3-D maps which will guide you to your destination whether it is by foot, bike, or car. The Bluetooth GPS is super easy to use and install.

All you need to do is insert the card into your device and you are ready to go. The Bluetooth GPS comes with optional accessories such as the wireless GPS receivers, car chargers, home chargers, and carrying cases.

Maps for the Tom Tom GPS navigator are updated daily and you can download the map you need 24 hours a day. The maps are purchased separately and downloaded to your GPS device. You can even download a fun Homer Simpson voice to give you door to door directions on your next trip.

These GPS Navigators are available in over 30 countries and in over 20 languages. The company has offices around the globe and is truly a leader in the GPS industry being on the forefront of this fast growing technology.

You can purchase Tom Tom Navigators of all kinds including the Bluetooth GPS at most retail stores that carry electronic products. You will also find many online stores which sell them.

The company provides a wide variety of personal GPS units for individuals and also provides professional navigation systems for businesses and fleet owners. No matter what your need or mode of transportation, even if by foot, Tom Tom GPS Navigator has you covered.

By Donald Stuart

How Are GPS Systems Useful?


The GPS tracking systems have been very useful for people to find their way on land and on water, in keeping track of people, vehicles, pets etc, in scientific studies, for map making, land surveying and countless other commercial uses. Everyday new applications are being found for the amazing NAVSTAR GPS commonly known as GPS systems.

Bascially you need a GPS receiver to receive and decode the signals that are continuously being sent by the 24 satellites orbiting the earth. The GPS system has been designed in such a way that any point of time your GPS receiver on earth receives signals from at least 4 satellites. This is essential for to determine your exact location on Earth.

GPS Systems Applications:

There are wide variety of GPS receiver models available suitable for a variety of applications. The US troops used this during the Operation Desert Storm. Now, imagine if they could find their way in the featureless, hot, empty deserts of a foreign country what you can do with your GPS system in your own city or country. You can hike and bike to remote locations and not be worried about being lost with a GPS receiver in hand.

Car GPS Systems:

The GPS systems for cars can be loaded with maps of the cities and countries of your choice and you can easily navigate and reach your destination with out having to stop and ask for directions. The car GPS systems are the most popular and widely used application of the available GPS systems. The GPS systems for car come with features like - maps, traffic information, places of interest - like shopping malls, gas stations, a local McDonalds, FM radios, local gas prices, accurate road trip information, entertainment and emergency road side assistance and much more. You can choose a car GPS system that suits your needs.

People GPS Tracking Systems

There are GPS systems for kids and also for elderly people. These tracking devices once strapped on these individuals continuously send you signals about their location. So you can easily trace them where ever they might wandered off to. Be it your old dad or your over-active toddler.

GPS Tracking Cell Phones

Want to locate your wife lost in a new city during Christmas shopping?- use your cell phone GPS tracking device. You could use the GPS feature on the cell phone to track her down! Many mobile phones come equipped with GPS devices.

Recently, a transplant patient who was in a concert and could not be reached by the hospital (the family's mobile phones were switched off) was eventually located as his mother's phone had a GPS device embedded in it. Emergency services tracked them down and got them to the operating table within a short time. Time is of essence in transplant cases and organs that match a particular patient are rare to come by. GPS saved the day in this case and life of the patient literally. This potentially life saving feature will in the near future be part of all mobiles phones. A recent law will soon require all mobile phones to have this device, so you can be tracked anywhere and located in case of an emergency.

By Vanessa Jones

What Is and How Does a GPS Work?

The Global Positioning System (GPS) is a satellite-based navigation system made up of a network of about 18-24 satellites placed into orbit. GPS was originally intended for military applications, but in the late 1970s, the government made a system available for civilian use. GPS works in any weather conditions, anywhere in the world, 24/7. There are no cost for the use.

How it works

GPS satellites circle the earth twice a day in the same orbit and transmit signal information to down to mother earth. GPS take this information and use triangulation to calculate the user's exact location. The GPS receiver compares the time a signal was transmitted by a satellite with the time it was received. The time difference tells the GPS receiver how far away from the satellite it is. Now, with this distance measurements from a few more satellites, the receiver can determine the user's position and display it on the unit's electronic map.

A GPS receiver must be locked on to the signal of at least three satellites to calculate a 2d position (latitude and longitude) and track movement. With four or more satellites in view, the receiver can determine the user's 3D position (latitude, longitude and also altitude). Once the user's position has been determined, the GPS unit can calculate other information, such as speed, track, trip distance, distance to destination, sunrise and sunset time and a lot more.

How accurate is GPS?

Today's GPS receivers are extremely accurate, thanks to parallel multi-channel design. Garmin's 12 parallel channel receivers are quick to lock onto satellites when first turned on and they maintain strong locks, even in dense foliage or urban settings with tall houses. Certain atmospheric factors and other sources of error can affect the accuracy of GPS receivers. Garmin® GPS receivers are accurate to 15 meters on average.
Newer Garmin GPS receivers with WAAS (Wide Area Augmentation System) capability can improve the accuracy to less than three meters on average. No additional equipment or fees are required to take advantage of WAAS. Users can also get even better accuracy with Differential GPS (DGPS), which corrects GPS signals to within an average of three to five meters. The U.S. Coast Guard operates the most common DGPS correction service. This system consists of a network of towers that receive GPS signals and transmit a corrected signal by beacon transmitters. In order to get the corrected signal, users must have a differential beacon receiver and beacon antenna in addition to their GPS.

The GPS satellite system

The 18-24 satellites that make up the GPS space segment are orbiting the earth about 12,000 miles above us. They are constantly moving, making two complete orbits in less than 24 hours. These satellites are travelling at speeds of roughly 7,500 miles an hour.

GPS satellites are powered by solar energy only. They have backup batteries onboard to keep them running in the event of a solar eclipse, when there's no solar power. Small rocket boosters on each satellite keep them flying in the correct path.
Here are some other interesting facts about the GPS satellites (also called NAVSTAR, the official U.S. Department of Defense name for GPS):

• The first GPS satellite was launched in early 1978.

• A full constellation of 24 satellites was achieved in late 1994.

• Each satellite is built to last about 10-15 years. Replacements are constantly being built and launched into orbit.

• A GPS satellite weighs approximately 1,500 pounds and is about 16 feet across with the solar panels extended.

• Transmitter power is only 50 watts or less.

What's the signal?

GPS satellites transmit two low power radio signals, designated L1 and L2. Civilian GPS uses the L1 frequency of 1575.42 MHz in the UHF band. The signals travel by line of sight, meaning they will pass through clouds, glass and plastic but will not go through most solid objects such as buildings and mountains.

A GPS signal contains three different bits of information — a pseudorandom code, ephemeris data and almanac data. The pseudorandom code is simply an I.D. code that identifies which satellite is transmitting information. You can view this number on your Garmin GPS unit's satellite page, as it identifies which satellites it's receiving.

Almanac data, which is constantly transmitted by each satellite, contains important information about the status of the satellite (healthy or unhealthy), current date and time. This part of the signal is essential for a good position view.

Sources of GPS signal errors

Factors that can degrade the GPS signal and thus affect accuracy include the following:

• Ionosphere and troposphere delays — The satellite signal slows as it passes through the atmosphere. The GPS system uses a built-in model that calculates an average amount of delay to partially correct for this type of error.

• Signal multipath — This occurs when the GPS signal is reflected off objects such as tall buildings or large rock surfaces before it reaches the receiver. This increases the travel time of the signal, thereby causing errors.

• Receiver clock errors — A receiver's built-in clock is not as accurate as the atomic clocks onboard the GPS satellites. Therefore, it may have very slight timing errors.

• Orbital errors — Also known as ephemeris errors, these are inaccuracies of the satellite's reported location.

• Number of satellites visible — The more satellites a GPS receiver can "see," the better the accuracy. Buildings, terrain, electronic interference, or sometimes even dense foliage can block signal reception, causing position errors or possibly no position reading at all.

• Satellite geometry/shading — This refers to the relative position of the satellites at any given time. Ideal satellite geometry exists when the satellites are located at wide angles relative to each other. Poor geometry results when the satellites are located in a line or in a tight grouping.

• Degradation of the satellite signal — Selective Availability (SA) is an intentional degradation of the signal once imposed by the U.S. Department of Defense. SA was intended to prevent military adversaries from using the highly accurate GPS signals. The government turned off SA in May 2000, which significantly improved the accuracy of civilian GPS receivers.

By Dagfinn Rognerud

Thursday, June 18, 2009

Never Lose Track of Your Vehicle With GPS Vehicle Tracking

Vehicles are an important asset to all individuals and businesses. A stolen or lost vehicle can be a cause of great concern to the owner. And if you are in a business that needs to have fleet of vehicles on the road then it gets all the more important to keep a tab on each one of them to increase productivity and profitability.

A GPS vehicle tracking system is the best way to track your vehicles, whether private or corporate. The device uses satellite signals or cell phone network to track vehicles. It is placed inside the vehicle which either provides real-time or passive information of the vehicle's whereabouts.

A GPS vehicle tracking system installed in the car emits a signal that is captured by the satellite and transferred to the monitoring system or the central server. You can either subscribe for real time monitoring display or you can opt for passive monitoring where you can retrieve the tracking information only after the vehicle reaches the company base.

Once there, the owner can retrieve the memory card from the system and view it on their personal computer. But if it's a real-time tracking system, which is much more convenient and useful, you can view the details of your vehicle such as speed, direction and location on the website of the GPS carrier. You can view this information on a gridded map or text format but maps are much easier to follow.

There are many benefits of a GPS vehicle tracking system and it may vary depending on personal or business use. The reasons for having a vehicle tracker installed in a private car can defer from that of corporate vehicles.

But one of the most important and common reasons to have a vehicle tracker is to locate your vehicle during car theft. Owners are always concerned about theft so with the help of these tracking systems you can easily locate the stolen car and inform authorities.

You can also display a sticker on your vehicle saying that your car is equipped with a GPS tracking system. This will be enough for most criminals to stay away from your car. Also one of the advantages of having these system installed is that most insurance companies offer discounted car insurance rates for vehicles having GPS tracking systems.

The newer GPS vehicle tracking systems can be used as navigation tools. With these systems your vehicle will always be on the right track and never be lost. These systems not only provide direction but also suggest alternate routes to avoid traffic congestion. You can also get information on available parking spaces and the nearest transport line.

By Landon Canista

GPS Tracking Systems - A Simple Guide to GPS's

There is an increasing number of GPS tracking systems on the market. Not all offer the same range of services though. These vary quite a lot depending on your needs.

Here is a simple review of various GPS tracking systems available on the market.

1. Car GPS - these are probably the best-known type of devices. The biggest names on the market are currently Garmin, Tomtom, Magellan and Mio, which together hold more than 80% of the market share of car GPS devices. Car GPS's normally come with preloaded maps for a specific country or area. Most new models also offer free map updates.

2. Hiking GPS - Designed for hiking, these focus more on geographic features rather than roads (unlike car GPS models).

3. GPS's for bikers are also in great demand. These are typically very resistant models and many come in weather-proof casings.

4. Boating GPS's are specialized models which vary in complexity depending on the needs. They also come with services like weather updates and other sea-specific information.

5. There are many more specialized GPS models designed with the needs of specific professions and activities in mind. For instance, there's been a lot of publicity recently around tracking systems as a way to have a permanent feeds for fleet tracking.

Here are 3 simple questions that anyone shopping for GPS's should ask themselves:

Question 1: What are your needs?

Of course, when it comes to shopping for GPS's, your choice will greatly depend on your needs. If you only need a model to fit in your car, then any commercial model should be okay. And you're spoiled for choice as far as car GPS models are concerned.

If however your needs are more specific, such as boating, hiking etc, then you should make sure to compare the different features available before making your choice.

Is the GPS covering the area you intend visiting, do you have access to features like weather services and map updates?

Question 2: What features do you expect?

Of all features, I feel that the presence of a map update facility is by far the most important. Not all GPS makers offer free map updates. Some require you to subscribe, at a monthly fee, to their service, before letting you download their stuff.

Others, like Tomtom, let you download a free update if it comes available 6 months after your purchase a new Tomtom GPS.

You also get a few GPS map providers that let you download maps free of charge.

Most of the recent models come with a host of features: slide show viewers, MP3 players, traffic update services, camera traps warning, weather update, digital radio. The list is almost endless. There's even a model that comes with digital TV (in case you fancy watching TV while driving).

They say it's called convergence: all your gadgets basically have more or less the same nifty features on them: your mobile phone can take digital pictures and play music, while your digital music player is a GPS tracker and can play slideshows.

But to me this is a classic case of too much of a good thing. If I need to play some music, chance are I will use my iPod. And if I need to take pictures, I'd rather use my digital camera rather than my mobile phone. And I won't be making phone calls with my iPod!

But do you really need all those features on your GPS? Well I guess it all depends on your age and how tech-savvy you are. If you are rather techno-phobic and the sight of buttons is enough to send shivers down your spine, I suggest you go for simple models with just one or two buttons (the Mio C520 is a great try).

Question 3: How much are you ready to spend?

Depending on the complexity of the model, a GPS should cost you from about $50 to a few hundred dollars. If you are after a GPS that does just what it should be doing (i.e. taking you from A to B in the simplest way), then I suggest you go for a simple and easy to use model.

It's important, when it comes to GPS tracking systems, to know your needs and the requirements of the task.

By Amene Katanda

GPS Systems Make Life Easier For All of Us

GPS - Global Positioning System is a satellite navigation system. First conceived as navigation aid by the military now number of GPS satellites broadcasts accurate timing signals by radio to GPS receivers.GPS provides a set of coordinates which represent the location of the GPS unit with respect to its latitude, longitude and elevation on planet Earth thus allowing them to accurately determine their location anywhere on the earth at anytime. It has become an important tool for map making and land surveying and is also used for very precise time reference needed for scientific research like the study of earthquakes. GPS receivers come in various formats, from devices integrated into cars, to phones to watches.

The GPS satellites broadcast accurate clock information in two forms:

Coarse Acquisition code/C/A-This is used mainly for civilian navigation which broadcast at 1,023 MHz repeating every millisecond. Each satellite sends a distinct C/A code, which allows them to be identified.

Precise code/ P-code- The P-code broadcast at 10.23 MHz, but it repeats only once per week. The P code is first encrypted into the Y-code, or P(Y), which can only be decrypted by units with a valid decryption key.

Applications of GPS:

There are number of fields where GPS has been used such as:

Military

It plays an important role in the military by helping to find precise targeting of military weapons such as missiles and precision guided munitions. It also provides good location awareness thus helping in controlling of forces and command.GPS satellites also carry nuclear detonation detectors.

Navigation

If you are someone who are likely to always get lost while driving then GPS is what you need in your car. It is used as navigation aid in cars, ships and planes. Hikers and trekkers use hand held GPS receivers to find their way. Even visually impaired people use this GPS equipment to guide their way.

Surveying

Construction workers also use GPS receivers for surveying the land to locate boundaries, structures, and survey markers, and for construction of roads.

Geocaching

GPS receivers are also used in recreational activities like geocaching where a hand held GPS receiver is used. Geocachers use this to travel to specific longitude and latitude walking or hiking to natural locations, searching for particular objects hidden by the other geocachers.
Aircraft passengers

Airline passengers can use GPS units in some airlines inside the aircraft except while landing and taking off as they have very little risk of interference. These airlines integrate aircraft tracking into the seat-back television entertainment system, available to all passengers even during takeoff and landing.

Precise time reference

For accurate time GPS is used. In time code generators GPS is used as a reference clock and also when sensors are deployed they are used to provide accurate time for each recording apparatus. Even atomic clocks are set to GPS time.GPS time is counted in days, hours, minutes, and seconds, in the manner that is conventional for most time standards.

Location-based services

Location based services also use GPS to locate all mobile phones. It provides a location solution is dependent more on mobile phones and less on telecommunications network topology. This also helps to provide specific location information to the mobile phone.

The biggest problem faced in GPS is that the atmospheric conditions can change the speed of the GPS signals while passing through the ionosphere. This effect gets minimized when the satellite is directly overhead and becomes greater toward the horizon.

By Jeffrey Meier

Thursday, June 4, 2009

GPS Tracking Devices Save You Time and Money


You know what they say, "Time is money." So if you can find a way to save both time and money, why not make the investment? A GPS device can do just that.

Whether you manage a fleet of trucks or a household, a GPS system can assist you as you try to get things done. Because everyone has a bottom line and no one wants to see money fly out of the window due to poor planning. GPS tracking can make route planning easier and get you to where you want to go with fewer hassles.

If you live in an area with heavy traffic, you know that shaving a few minutes of driving time here and there means you spend less time on the road and more time doing the things you really want to do. Even if you are not in an area with heavy traffic, your time is valuable and you probably don't want to spend more of it on the road than you have to.

A GPS tracking device can give you the most efficient route to reach your destination. Not only will you save time, but you'll also save on fuel. And that really is a big deal. As you try to combine errands and get the most out of a tank of gas, it only makes sense to make sure you are not taking some route that causes you to spend more time idling at traffic lights than necessary. A GPS device can give you information on routes that you can travel with fewer stops and starts.

By Nancy McCord

Wednesday, June 3, 2009

GPS Devices - How Do They Work?

Unless you've been living under a rock, you certainly have heard of the Global Positioning System or GPS. There is a GPS for almost everyone: for hikers, drivers, bikers etc. You also find GPS modules on some advanced mobile telephones like the Nokia 6110 Navigator.

What is it?

In very simple terms, the Global Positioning System (GPS) uses radio signals from 4 satellites to locate the exact position of anything on Earth.

What does it cost?

Apart from the cost of buying one, using a GPS is free of charge. In fact some of the most basic GPS do just what they are about: guiding the driver from A to B via a graphic interface.

The most recent models come with a range of functions (MP3 player, slideshow, video player, blue tooth kit, and even digital TV!).

Some GPS have pre-installed POI (points of interest) such as garages, restaurants, parking etc. GPS makers have also added new value-added services such as live traffic update or a weather services like Tom-tom Weather on the GO 530/730/930).

You will need a subscription to most of those services however. Typically an annual subscription costs around $50, with unlimited updates.

Other options are free for a limited period only (for instance when a new map becomes available within 30 days of buying a new GPS, Tom-tom will let you download the map free).

What to look for?

• Ease of Use. If you are not too comfortable with gadgets, you might prefer going for a simple model. One that simply guides you from A to B without all the extras.
• Traffic Info. Some GPS offer real time info on traffic jams or road works. The GPS then recalculates your route - and offers an alternative one. These services are often charged so you'd better check before buying!
• Speed Cameras. Most GPS's come with a pre-installed list of speed cameras. And again here, you will need some form of subscription to update that list with new cameras.
• Maps. Some GPS only cover a limited geographic area. Others have more extensive maps like the Tom-tom Go 730. This type will be particularly useful for your holidays abroad. New maps can also be purchased as CD ROMs or on pre-loaded memory cards.

You can also download off the website of most GPS makers. After download, you then transfer the maps onto the GPS using either a memory card, a USB cable or a Bluetooth kit (if your GPS has Bluetooth).

• Screen Size. This usually varies between 3.6 and 4.3 inches. As a rule, especially for car GPS, information on the screen should not be too hard to read. But this should not be a problem considering that most new GPS's come with voice navigation.

By Amene Katanda