GPS Accessories

Why Do I Need an External Antenna for My PocketPC?
By Jon Butt

For stronger signal strengths, lesser static interruptions, and better GPS reception and accuracy, use an external antenna. PocketPC gadgets from HP iPAQ, Dell, and Palm, especially those with cellular phone and GPS capabilities, can work better with various signal enhancers.

An external antenna is one of the numerous PDA handheld accessories along with PDA cases, screen protectors, styluses, car mounts, cables, and others that ensure total Pocket PC protection and improved functions.

External Antennas For PocketPCs - Promoting Seamless Connectivity

For PDAs with cellular phone and GPS (global position system), an external antenna can work wonders. An external antenna can be attached to the Pocket PC device and can be conveniently placed on the roof of your car, at the top of your desk, etc. An external antenna for your Pocket PC can utilize more signals making communication faster and more convenient.

Even though some Pocket PC units, PDA phones, and cellular phones have their built-in antenna, an external one is still useful.

A built-in antenna has certain limitations in sending and receiving signals because of its restricted size so the user has to find the right place to conduct his call or use the GPS of his Pocket PC. An external antenna can easily get better signals because it can place itself in a better radio frequency (RF) environment.

Various points should also be taken care of before connecting an antenna to your Pocket PC. Other PDA accessories, like cables or connectors, are needed to connect the antenna to your Pocket PC.

Longer handheld cables lessen the signals, so shorter cables should be chosen where possible. The location of the external antenna should also be considered. For example, when you’re on the road, the perfect spot to put the Pocket PC antenna is on the roof of the vehicle to widen handheld signal coverage.

Jon Butt is the publisher of http://www.the-PDA-guide.com One of the web's leading sources of information on how to choose your perfect PDA or PocketPC or Handheld, where to get the biggest discounts online, which software downloads will enhance your life and what accessories will enhance your little PDA friend.

Article Source: http://EzineArticles.com/?expert=Jon_Butt

GPS for GOLF

1. Golf GPS Systems - Gadgets to Improve Your Game
By Sarah Freeland

One of the newest tools of the trade is the golf GPS (global positioning system). These tools provide golfers with course maps and they can be used for determining yardage. There are several different models of golf GPSs including handheld GPS system models and digital caddies. These golf gadgets have become so popular in the last couple of years that now many of the top golf courses offer digital caddies that have a gps integrated into their golf cart rentals.

If you are in the market for a handheld GPS then you have several great options to choose from. Your first option is the Sky Golf – Sky Caddie SG2 GPS. This handheld model has a list price of $349.99, however, you can occasionally find it on sale for around $280. This product includes a programmable GPS rangefinder, an AC battery charger, a USB cable to connect your GPS to your computer, software, a belt clip, and a quick start guide.

If you have a pocket PC then you might be interested in the GPS Golf Pro with Bluetooth GPS Receiver. This item has a list price of $350, however, it is commonly available for a much lower price. It offers an electronic scorecard, shot by shot tracking, club recommendations, GPS distances, and scorecard email.

If you are looking for an easy to use handheld GPS then you may be interested in the SONOCADDIE GOLF GPS SYSTEM. This product sells for around $300. It offers distance tracking for several items like targets, hazards, and distances to the green.

Golf GPS devices are great golf cart accessories and they can be a great gift to give to yourself or to someone else. When you shop for a golf GPS make sure that you try a few out to see which ones you like best. Make sure that you can read the display and make sure that you are able to use all of the buttons or stylist. You will also want to shop around and compare prices, as this can help you to save $50 to $100 on a single golf GPS model.

Are you in the market for golf accessories? Fore Her Golf carries clothing and accessories with a feminine appeal including polo shirts, skirts, golf GPS devices, hats and outerwear from top brands - also a great selection of unique golf gifts and memorabilia for the lady golfer in your life. Fore Her Golf is your source for women's golf supplies and gifts, products reviews and recommendations as well as game tips and training techniques. For more information on golfing and other recreational activities visit the golf directory.

Article Source: http://EzineArticles.com/?expert=Sarah_Freeland

2. Improve your golf game with StarCaddy.
Choosing the right club can make or break your game. StarCaddy's s unique PDA-based software and hardware helps you choose the best club for every shot. StarCaddy software displays a digital map of the course on your PDA, using GPS to give you the exact distance to the green, sand traps, or any other course feature. Analyze the key elements of the course to improve your club selection and game with just a tap on your Palm or PocketPC PDA.

StarCaddy helps golfers Choose the Best Club For Every Shot!

Take the Guesswork Out of Your Game.
With GPS and a sophisticated digital map you can analyze the distance for every shot you make. Use StarCaddy to determine exact yardage to any course feature and take the guesswork out of your game.

Lay Up or Go For It? The Right Decision Every Time.
What's the landing area between two bunkers? Can you make it over the pond? With StarCaddy, there's no more worrying about hazards or long shots. With its precise measurement tool, you can judge distances perfectly and choose the perfect strategy every time.

X Marks the Spot.
When using a GPS Receiver, StarCaddy pinpoints your position on the course with an X. As you move, StarCaddy automatically zooms in to display increasing detail and the precise distance from you to the green at all times.

Keep Score with StarCaddy.
StarCaddy lets you track your game with precision. With a tap of the screen, you can view the tees, yardage and handicap for each hole. StarCaddy dynamically calculates In, Out and Total scores, tracks match status (including strokes given per hole) and will even record presses and side bets. So relax and let StarCaddy keep score for you or your foursome.

Play Any Course Like It's Your Home Course.
Stop trying to interpret maps and legends. StarCaddy's digital maps are accurate and easy to read. These maps are created from satellite and aerial imagery and are geo-referenced to be within one yard of actual position. And since StarCaddy can give you the exact distance to each course feature, every course, you can master the grounds in no time. Every course will feel like your home course!

Download your first StarCaddy course map for free!
Getting started with StarCaddy is easy! Check out all the digital course maps available at www.starcaddy.com, then pick the ones you want. Your first map is FREE with your purchase of StarCaddy. You can download detailed digital maps for the courses you play at home, on vacation or when you're traveling on business.

Use StarCaddy's MapManager to efficiently control your list of digital course maps. MapManager is a program for your desktop computer that installs StarCaddy on your PDA and lets you easily move your course maps on and off your PDA. MapManager stores your course maps when they're not in use and checks for FREE updates to the maps and the StarCaddy software.

StarCaddy is optimized with a GPS receiver.

According to an informal survey of golf pros, the average golfer loses as many as six strokes per round to incorrect club selection. StarCaddy uses GPS satellite technology to give golfers the information needed to choose the right club every time and pick up strokes without practice.

Star Caddy for PDA w/ GPS Receiver and Software

System requirements for the desktop PC:
OS: Win 95/98/2000/ME/XP (Home or Professional)/NT
Internet Access required: IE 5.0 or higher OR Netscape 4.0 or higher
Sync Software: Active Sync 3.1 or higher (for Pocket PC models)
PalmDesktop 3.1 or higher (for Palm OS models)

For more detail click here.

Dowload Plugin

* SVG Viewer - Display graphic format SVG from Adobe
* TIFF Viewer - โปรแกรมช่วยแสดงผลเอกสารในฟอร์แมต TIF มีฟังก์ชันซูมภาพ ช่วยให้อ่านเอกสารได้ชัดเจนตามต้องการ
* Flash Player - โปรแกรมแสดงสื่อมัลติมีเดียในฟอร์แมต Flash Movie ที่ได้รับความนิยมสูงในปัจจุบัน
* QuickTime Player - โปรแกรมแสดงสื่อวิดีทัศน์ (VDO) ในฟอร์แมต .mov จากค่าย Apple
* Real Player - โปรแกรมแสดงสื่อวีดิทัศน์ (VDO) และไฟล์เสียง (Audio) ในตระกูล .rm
* Windows Media Player - โปรแกรมแสดงสื่อวีดิทัศน์ (VDO) และไฟล์เสียง (Audio) จากค่ายไมโครซอฟต์
* Multimedia e-Book Reader - โปรแกรมแสดง e-Book ในรูปแบบสื่อมัลติมีเดียจากค่าย Desktop Author
* FlipViewer - โปรแกรมเบราว์เซอร์สำหรับการแสดง FlipAlbum

What is Geocoding?

By Dave Stevenson

"Geocoding is the process of assigning geographic coordinates (e.g. latitude-longitude) to street addresses, as well as other points and features. With geographic coordinates, the features can then be mapped and entered into Geographic Information Systems." (http://en.wikipedia.org/wiki/Geocoding)

How do I Geocode an Address?

There are a number of ways to geocode an address. The complicated way is to download the US Census data (Tiger/Line), write some programming code and database code to interact with the database, and go from there. The much easier way is to use an existing geocoding provider. There are many on the net today. Many have programming interfaces in Java, .NET, or even Ruby, ready for you to plug into your application.

What are some uses of Geocodes?

Many people ask why addresses should be geocoded. Let me ask you this: Have you ever wanted to generate a list of customers that lived within a certain distance from a point? Or have you wanted to display on a map where your customers are from? Both of these questions require you to geocode your data in order to find the answer. When you have an address geocoded, you can then use the latitude and longitude to perform searches and mappings with it.

Dave Stevenson is a computer programmer from Highland Utah. He has many hobbies, including running. Check out his website at Geocode America

Article Source: http://EzineArticles.com/?expert=Dave_Stevenson

Topographic Maps 101

By Will Robertson

The intricate details on a topographic map can be befuddling, even frustrating, if you are learning while out in the backcountry. But once you get familiar with the markings and symbols, reading maps will become a friendly aid, rather than a dreaded assignment.

Topographic Maps Grid System

Lines of latitude run parallel to the equator (east and west), and lines of longitude run perpendicular to the equator (north and south). These lines form a pattern of squares across the surface of the earth like a checker board.

One square, formed by lines of longitude and latitude, measures 90 degrees x 90 degrees. Degrees are further subdivided into minutes and seconds.

• 1 degree = 60 minutes
• 1 minute = 60 seconds

The important thing to understand, when we look for a topographic map for our hiking adventures, is that it will be located within this larger context of degrees, minutes, and seconds. Fortunately, it will also, usually, be identified with a place name.

An alternative method of notation within the Geographic Coordinate System is the decimal degree system. In the decimal degree system, minutes and seconds are replaced by a percentage of a degree, expressed as a decimal up to four places long. It is often used for Geographic Information Systems (GIS) applications,

Topographic Maps Scale Explained

A topographic map lists its scale in the margin or legend. The scale is the relationship between distances on a map and the corresponding distance on the ground. For example, a map with a scale of 1:50,000 means that 1 unit of measurement on the map equals 50,000 equivalent units on the ground.

Units can be in inches, feet, centimeters, or meters, depending on what scale map you are looking at and what measuring system the country uses. Most USGS maps are 1:24,000, also known as 7 ½ minute maps. On this map, 1 inch = 24,000 inches on the ground. In Canada, most hiking maps are 1:50,000 scale, where 1 cm = 50,000 cm on the ground.

A small scale map (ex. 1:100,000) covers a large area; it shows less detail with fewer features. A large scale map (ex. 1:10,000) covers a small area; it shows great detail and small features. A 1:2,500, large scale map would show individual houses and street lights.

Topographic Maps Symbols and Colors

The symbols and colors used on Topographic maps are fairly straight forward:

• Black - man-made, “cultural,” features such as roads, buildings, etc. It is also used to show geographical names (toponymy), certain symbols, geographic coordinates, precise elevations, border information and surround information.

• Blue –water, lakes, rivers, streams, etc. The names of bodies of water and water courses are also shown in blue, as are magnetic declination and UTM (Universal Transverse Mercator) grid information.

• Brown - contour lines, contour elevations, spot elevations, sand.

• Green - areas with substantial vegetation like a forest, orchard, or vineyard

• Grey - used on the back of the map where the different symbols and a glossary of terms and abbreviations can be found.

• Orange - unpaved roads and unclassified roads and streets.

• Purple - features added to the map since the original survey. These features are based on aerial photographs but have not been checked on land.

• Red - major highways; boundaries of public land areas. A red tint is used to show an urban development.

• White - areas with little or no vegetation; also used to depict permanent snowfields and glaciers

Topographic Maps Glossary

• Bearing - Angular direction expressed in degrees.

• Contour Lines – A line on a map joining points of equal elevation. These lines are used to illustrate relief on a map.

• Distortion - The difference in shape between the actual curved surface of the earth and the flat representation of a topographic map.

• Grid - A system of horizontal and vertical lines that provide coordinates for locating points on an image.

• Magnetic Declination - The angle between magnetic north and true north, expressed in degrees and minutes, east or west from true north.

• Magnetic North - The direction your compass needle points.

• Projection - A method by which the curved shape of the earth is represented on a flat surface, overcoming distortion.

• Relief – The variations in elevation of the earth’s surface.

• Scale – The relationship between distance on a map and the corresponding distance on the ground. For example, a map with a scale of 1:50,000 means that 1 unit of measurement on the map equals 50,000 equivalent units on the ground.

• Topographic Map – An illustration of the earth’s different elevation levels by means of contour lines. They present both natural and manmade features.

• True North - Direction of the northern rotational axis of the earth – the North Pole.

Outdoors Adventurer, Writer and Webmaster Will Robertson lives with his family in Little Rock, Arkansas.

Explore the best hiking vacations and gear on the planet at: http://www.hiking-vacations-and-gear.com

Article Source: http://EzineArticles.com/?expert=Will_Robertson

OnStar Satellite System for Robotic Vehicles

By Lance Winslow

The General Motors OnStar system is a cool system for any family. There is even the ability to unlock your door from Space, if you lock yourself out of your car you simply call a number and they unlock the door. With this great technology and the fact it always knows where you are with GPS means the OnStar system could do much more, if it were designed to do so. For instance OnStar Satellite System could be used for Engine Efficiency, self-driving buses, over the road trucks, train controls or even street sweepers at night and Garbage Trucks in the early mornings.

With GIS information data sets figured into the GPS Navigational system it would be easy to control unmanned ground vehicles in our civilization. There is a shortage of truck drivers and cities need to cut labor costs. Many of our Nations Largest Municipal Transportation Systems have had strikes in the last year. Additionally with fuel costs up, we must cut costs somewhere. By over laying map systems, ESRI software and XML database sets this system can be integrated and that is not a problem. Thus taking care of the coming shortages in drivers and the escalating labor costs, which threatens to sink our nations most critical transportation systems.

There would also be military applications for this to save fuel and increase range on the heavier bullet proof re-enforced Humvees. Indeed as we saw in the DARPA Challenge all these technologies are fully feasible and during that event much of this technology was not even used or allowed due to contest rules. These systems for true autonomous ground transportation along with anti-collision devices now available by German and Japanese Automakers this whole plan could be a done deal in relatively short order.

This could also prevent wartime deaths from roadside bombs and be used for robotic warfighting vehicles especially for army tanks, robotic vehicles and UAVs too. By developing these systems and technologies to the fullest we maybe able to allow for the transfer technology to the private sector to insure a greater advantage in efficiency in Ground Transportation, think on this.

"Lance Winslow" - Online Think Tank forum board. If you have innovative thoughts and unique perspectives, come think with Lance; www.WorldThinkTank.net/. Lance is a guest writer for Our Spokane Magazine in Spokane, Washington

Article Source: http://EzineArticles.com/?expert=Lance_Winslow

Satellite and Satellite Phones

By Paul Cris

A satellite is a most sophisticated communication device, which works as a relay station orbit up above the earths crust. All satellites have receivers, converters and transmitters with all the accessories needed for wireless communication. A typical communication satellite has 12 to 24 on board transponders. A Transponder is nothing but a package consisting of receivers, converters and transmitters and the normal output is calculated between 5 to 10 watts. It has the potential to operate in L-Band, C Band or KU Band or in the microwave range. KA-bands (18 to 31 GHZ) can also be operated in some cases. Communication through Mobile satellite system cannot be operated.

Geosynchronous Earth Orbit Satellite – GEO:

It is a satellite which orbits the earth some 22000 plus miles up above the equator. It is having a fixed direction corresponding to Earth. It is finely synchronized with the rotational speed of Earth so much so it would appear as though it stands stationery at that spot all the time. Earth-satellite-Earth time is about 0.25 seconds. Normal Bands operate on 4 to 6 GHZ (C-Band) and 12 to 14 GHZ (KU-Band normal frequency is 10.9 to 17 GHZ). Signals that go beyond 3 GHZ are considered microwaves.

Low Earth Orbit Satellite – LEO system.

In this system a constellation consisting quite a large number of satellites put on a circular orbit above the earths surface at a constant altitude of a few hundred miles (as against 22000 plus miles in GEO). The entire constellation is systematically arranged in such a way that at least one satellite in on sight always. Every geographical area is covered by the orbiting satellites. Internet access though wireless is possible in this configuration. L. Band - 0.5 to 1.5 GHZ – is operated which means satellite phone handset to satellite in quite possible.

Medium Earth Orbit Satellite: MEO

It is not stationery from a fixed or definite point on earths orbit like a GEO. In fact it is between a GEO and LEO. You need access methodology to access the satellite or use a precise frequency band in order to track the satellite with the help of a non-direction antenna.

Paul has been providing answers to lots of queries through his website on a wide variety of subjects ranging from satellite phones to acne. To learn more visit http://www.askaquery.com/Answers/qn1692.html http://www.askaquery.com/Answers/qn1692.html

You are welcome to republish the above article only if you add our hyperlinked URL.

Article Source: http://EzineArticles.com/?expert=Paul_Cris

Where in the World Is...?

By Aaron Wittersheim

With Internet use spreading across the globe, one advertising message no longer fits all. Believe it or not, Asians, Europeans and Latin Americans account for more than 60 percent of all Web traffic, and the percentage is climbing. At the same time, Internet shoppers everywhere are becoming increasingly hostile to generic pop-ups and banners. So, how can on-line advertisers get results in such a complex and demanding marketplace? A big part of the answer is geo-targeting.

Geo-targeting means gearing ad content to a specific geographic market. Advertisers can identify on-line shoppers by IP address, postal code or area code; when the shopper visits the advertiser’s site, he will see an ad that literally hits him where he lives. Several geo-targeting approaches are available:

Advertising on Web sites with localized content, such as on-line newspapers, yellow pages and entertainment guides; Advertising on sites such as Yahoo!®, where user registration includes geographic markers; Using third-party advertising services such as DoubleClick; and Advertising on sites with geographically specific content, such as MapQuest® and The Weather Channel.

Creating ads in local languages, while important, is only one aspect of geo-targeting. International companies geo-target by adjusting prices to compensate for currency exchange rates. They also display order and response forms in local currencies to make them better understood and more effective. Subtle changes in ad design can make a big difference as well; for example, when targeting Canadians, far higher response and conversion rates occur when a small red maple leaf appears in the ad.

Even within the U.S. market, geo-targeting grows in importance. Studies indicate that most shoppers—even on-line shoppers—prefer to purchase within 10 miles of home. Thus, geographically sensitive businesses, such as real-estate developers, franchisers and car dealerships, can geo-target and reach an extremely receptive segment of potential customers.

Although geo-targeted ads are expensive compared to the one-size-fits-all variety, their increased effectiveness more than offsets the cost. With $5 billion expected to be spent on local on-line advertising by 2010, technology is gearing up. The newest version of IP addresses, Ipv6, will assign a unique identifier to every computer, making geo-targeting more accurate. Geo-targeting service providers are cropping up all over, and Internet powerhouses like Google™ AdWords™ and Yahoo!® Search Marketing already offer easy-to-use geo-targeting ads, tracking and analytics.

Companies should consider this new advertising strategy before the competition catches on and gets to the customers' door first.

Aaron Wittersheim is president of Whoast Inc., a suburban Chicago search marketing firm. For more information, visit http://www.whoast.com

Article Source: http://EzineArticles.com/?expert=Aaron_Wittersheim

Download Plugins

* Adobe Acrobat Reader - Display PDF file format from Adobe.
* Adobe Acrobat Reader Mobile - Display PDF file format from Adobe.
* Flash Player - Display multimedia format Flash Movie from Adobe.
* Adobe Shockwave" - Display SWF file from Adobe.
* SVG Viewer - Display graphic format SVG from Adobe.
* TIFF Viewer - Display graphic format TIF with Zoom in-out function.
* QuickTime Player - Display video format (MOV) from Apple.
* Real Player - Display video and audio format (RM) from Real.
* Windows Media Player - Display video and audio formats from Microsoft.
* Multimedia e-Book Reader - Display multimedia e-Book from Desktop Author.
* FlipViewer - Browser for display FlipAlbum.

GIS for Accident Report

Traffic Report and Accident Management System (TRAMS) is the gis project for accident report developed by Ministry of Transport, Thailand.

This project aims to centerized accident data that happend on highways.

For more details please visit at TRAMS website.

ATOMIC CLOCKS

By Charles Truett

The first atomic clock came into existence in 1949. The U.S. National Bureau of standards was the home of this prototype of modern atomic clocks. The first accurate atomic clock was designed in 1955. This clock was based upon the transition of the caesium-133 atom. The discovery of this technology was the basis if the internationally agreed upon second. The United States has an official clock, an atomic clock, that is responsible for the accuracy of time throughout the country and is working in conjunction with clocks around the world to ensure that time is kept in unison across the globe.

Today we can find atomic clocks for our homes, offices, and electronic devices. These highly popular clocks can be purchased from your local retailers or from reputable online merchants who specialize in bringing you only the best, most precise timepieces around. Various styles and designs will make it easy for you to choose the atomic clock that best suits your needs. The atomic clocks used by government entities are by far the most accurate, but personal atomic clocks are highly reliable and you will be certain that you always know exactly what time it is at any given moment.

When shopping for an atomic clock, keep in mind that versions available to the general public are not suitable for scientific calculations, but instead a personal asset and a symbol of precise decisiveness. You can find an atomic clock in any price range and in many styles. An atomic clock makes a great conversation piece and will be a stylish addition to your home or office. Taste, style, and precision are what you will find when you begin your search for the perfect atomic clock. Great deals and numerous choices are a click away.

You can now buy clocks online! To view our complete and comprehensive selection of atomic clocks, please visit: amazon.com

Article Source: http://EzineArticles.com/?expert=Charles_Truett

Atomic Clock
By Wikipedia
An Atomic Clock is a type of clock that uses an atomic resonance frequency standard to feed its counter. Early atomic clocks were masers with attached equipment. Today's best atomic frequency standards (or clocks) are based on absorption spectroscopy of cold atoms in atomic fountains. National standards agencies maintain an accuracy of 10-9 seconds per day (approximately 1 part in 1014), and a precision equal to the frequency of the radio transmitter pumping the maser. The clocks maintain a continuous and stable time scale, International Atomic Time (TAI). For civil time, another time scale is disseminated, Coordinated Universal Time (UTC). UTC is derived from TAI, but synchronized with the passing of day and night based on astronomical observations.

History
The first atomic clock was built in 1949 at the U.S. National Bureau of Standards (NBS). The first accurate atomic clock, a cesium standard based on a certain transition of the cesium-133 atom, was built by Louis Essen in 1955 at the National Physical Laboratory in the UK. This led to the internationally agreed definition of the second being based on atomic time.

For decades, scientific-instrument companies, such as Hewlett-Packard, have been making cesium-fountain clocks for entities like NIST and USNO, at prices rivalling those of cars.

In August 2004, NIST scientists demonstrated a chip-scaled atomic clock. According to the researchers, the clock was believed to be one hundredth the size of any other. It was also claimed that it requires just 75 mW, making it suitable for battery-driven applications. This device could conceivably become a consumer product. It will presumably be much smaller, much less power-thirsty, and much cheaper to make than the traditional cesium-fountain clocks used by NIST and USNO as reference clocks. However, it is uncertain whether it will ever become a consumer product.

How they work
Frequency reference masers use glowing chambers of ionized gas, often cesium because that is the element used in the official international definition of the second.

Since 1967, the International System of Units (SI) has defined the second as the duration of 9 192 631 770 cycles of the radiation which corresponds to the transition between two energy levels of the ground state of the cesium-133 atom. This definition makes the cesium oscillator (often called an atomic clock) the primary standard for time and frequency measurements (see cesium standard). Other physical quantities, like the volt and metre, rely on the definition of the second as part of their own definitions. [1]

The core of the atomic clock is a tuneable microwave cavity containing the gas. In a hydrogen maser clock the gas emits microwaves (mases) on a hyperfine transition, the field in the cavity oscillates, and the cavity is tuned for maximum microwave amplitude. Alternatively, in a cesium or rubidium clock, the gas absorbs microwaves and the cavity contains an electronic amplifier to make it oscillate. For both types the atoms in the gas are prepared in one electronic state prior to filling them into the cavity. For the second type the electronic state of leaking atoms is detected and the cavity is tuned for a maximum of detected state changes.

This adjustment process is where most of the work and complexity of the clock lies. The adjustment tries to correct for unwanted side-effects, such as frequencies from other electron transitions, temperature changes, and the "spreading" in frequencies caused by ensemble effects. One way of doing this is to sweep the microwave oscillator's frequency across a narrow range to generate a modulated signal at the detector. The detector's signal can then be demodulated to apply feedback to control long-term drift in the radio frequency. In this way, the quantum-mechanical properties of the atomic transition frequency of the cesium can be used to tune the microwave oscillator to the same frequency, except for a small amount of experimental error. When a clock is first turned on, it takes a while for the oscillator to stabilize.

In practice, the feedback and monitoring mechanism is much more complex than described above.
Historical accuracy of atomic clocks from NIST.
Historical accuracy of atomic clocks from NIST.

A number of other atomic clock schemes are in use for other purposes. Rubidium standard clocks are prized for their low cost, small size (commercial standards are as small as 400 cm³), and short term stability. They are used in many commercial, portable and aerospace applications. Hydrogen masers (often manufactured in Russia) have superior short term stability to other standards, but lower long term accuracy.

Often, one standard is used to fix another. For example, some commercial applications use a Rubidium standard slaved to a GPS receiver. This achieves excellent short term accuracy, with long term accuracy equal to (and traceable to) the U.S. national time standards.

The lifetime of a standard is an important practical issue. Modern Rubidium standard tubes last more than ten years, and can cost as little as US$50. Cesium reference tubes suitable for national standards currently last about seven years and cost about US$35,000. The long-term stability of hydrogen maser standards decreases because of changes in the cavity's properties over time.

Modern clocks use magneto-optical traps to cool the atoms for boosted precision

Notebook GPS

Best PC Pocket GPS
By Dan Ayala

Stop Getting Lost

One of the greatest uses for a pocket pc is for gps navigation. Now all those people who continually get lost can find their way anywhere with the various types of gps navigation software available. No longer will they have the excuse of not wanting to ask for directions. The directions are easily accessible from their palm pilot.

The best pocket pc gps software has a gps receiver with it. This allows you to receive constant updates. Many of the best software products for your ipaq have some other great features, too. Some of these features include detailed maps for roads and streets in the U.S., Canada and Europe. These maps can be downloaded to and from your computer and often allow you to enter personalized information.

Other gps navigation software offers topographical maps, aviation maps and marine maps. For whatever kind of travel you do, there is a gps system for your pocket pc that will work splendidly. You no longer have to worry about being lost hiking in the mountains, flying a small personal aircraft or piloting your own boat.

The best gps software packages have extremely detailed voice guidance to keep your eyes on the road instead of on your pda. This safety feature should impress even the most careful driver.

Having gps navigation software on your pocket pc makes the world a much smaller, safer place to be and a heck of a lot easier to navigate. So, find the best pc pocket gps for you and never get lost again.

Buy PockPC, Notebook and GPS at amazon.com.

Article Source: http://EzineArticles.com/?expert=Dan_Ayala

GPS Reviews

The Garmin 350 is a great GPS for the price "now". My friend purchased the same model during Jan/Feb-07 for over $900 CDN. It was very simple to use and really didn't require much instruction. After a few minutes of playing with it, the system was able to locate my position and it was ready to go. After using it for a few weeks...I love this GPS. I decided to order the Gilsson External Antenna (Model MCX with 3fts wire)to increase my reception around the town.

Great price at Amazon....even my wife "The Living GPS" was impress by this little gadget.

GIS for Real Estate

By Harry E. Davis

GIS stands for "Geographic Information Systems." A geographic information system is used for capturing, storing, analyzing and managing data and associated attributes which are referenced to a given point or place. Many local governments have begun to establish these systems for use within their borders and a GIS provides a central access point for geographic information not only for government employees, but also for web users. Austin, Texas has had a sophisticated GIS online for several years.

One advantage for a government entity in setting up a working GIS site is that it provides customers an online way to get various types of information on the web without calling or having to drop by the office, thereby freeing up employees for other tasks. The consumer gets an advantage by being able to view a lot of maps, such as zoning maps, online instead of having to purchase one.

GIS is a great tool for real estate agents, appraisers, buyers and anyone else with a need to look up information about a property, and GIS is becoming more widespread every day. If you live in a medium to large size city, chances are very good that your local city or county planning department has a working GIS right now. Even many small towns have them.

GIS enables the visitor and the real estate professional to view zoning maps, parcel maps, flood maps, aerial photos, and a variety of other information which can be viewed separately or as a grouping of layers on the same map. Most GIS systems provide an address search capability. For some types of properties it may be necessary to zoom in from a map of a larger area. Tools to zoom in and out are always provided.

In an example situation, suppose you search for a home by address and find it on the map. You can then choose from several map layers to add to it from a menu, such as zoning, parcel maps, bodies of water, and more. If you choose to overlay flood zone maps, you will be able to tell if the home lies with a flood plain. This gives the user a way to know if the home is likely to require flood insurance. If you want to know the specific zoning for the home, you can choose to have that map layer added on top. These map "layers" are mostly transparent, meaning that the original map will still be visible.

The local city planning department GIS systems and their corresponding menu systems vary according to the design and the provider, but I have accessed several in my area and found them to be more or less the same in terms of how they operate and they types of information they provide. The beginning GIS user may find these online systems a little confusing at first, but a few experiments should help you to find your way around. These systems continue to evolve to make them easier for nontechnical users to operate. The wealth of useful information they provide makes them well worth the effort to learn.

To locate a GIS for your city, go to your favorite search engine and type in the name of the city and GIS, such as " Austin GIS" in the search box. If you don't find your local GIS this way, go to the city or county web site and look for it there or just contact their office and find out if one exists and where to find it.

Harry E. Davis is a Texas state certified residential real estate appraiser in business since 1975 and serving the Austin Texas metro area. His web site is located at Austin Texas Appraiser. Services are available in other Texas cities at El Paso Texas Appraiser and Fort Worth Texas Appraiser

Article Source: http://EzineArticles.com/?expert=Harry_E_Davis

Raster to Vector Conversions

By Rohini Sood

With rapidly increasing technologies more and more companies are searching for new ways to gain a lead in the market, raster to vector (R2V) conversion is becoming a standard of expectation. Raster to Vector conversion also known as R2V caters to the diversified fields ranging from commercial to industrial. More than 60 countries use R2V for mapping and GIS data conversion applications. Architectural, engineering, construction, electrical and house plans are all regulars of the raster to vector conversion. The raster to vector conversion can be applied to convert data or image into vector format. The advantages of raster to vector (R2V) conversion include: A vector image has no jaggedness, no loss in detail and can be printed at any resolution or any size.

This vector image can be scaled up or down without any loss in quality.

Also the archive of the vector artwork can be used for manuals, brochures, newspapers and a host of other areas.

Raster to vector conversions enables you to convert technical drawings, maps logos and any other graphics from raster to vector formats, for easy archiving and instant access. Raster to vector (R2V) procedure can be used to process charts, drawings, maps, schemes and other similar images.

Applications:

Raster to vector conversion of Technical Drawings (AEC)

Raster to vector conversion of House plans

Raster to vector conversion of GIS (CAD)

Raster to vector conversion of Blueprints

Raster to vector conversion of Logos

Vectorization for website applications

Vectorization for Graphic Design purposes

One of the many ways to achieve the raster to vector conversion can be recreating the vectorized output using AutoCAD (DWG, DXF), MicroStation (DGN), Adobe Illustrator (AI), CorelDraw (CDR), VectorWorks, etc.

Article Source: http://EzineArticles.com/?expert=Rohini_Sood

Digital Globe

By Peter Emerson
Globes are the spherical version of a map. Their spherical shape allows them to represent the earth perfectly. Globes were always in used as navigational tools as well as to understand various earth’s processes and phenomena.

The earliest globes were traced to the fifteenth century. Like maps, globes also show accurate directions, dimensions, distances, shapes and sizes of all the countries in the world. Most globe-makers use high quality geographic research and cartographic abilities to design globes. They are also updated regularly to take note of any changes in the world’s political, social, or environmental conditions.

Digital globes are those which use advancements in digital technology for representing the earth better. They have digital images over and inside the screen that keep changing as per the user’s requirements. The images, derived from satellite images, are made to appear on the screen, which is similar to a picture screen of a television. There are also digital raised-relief globes with clearly defined mountain ranges and water bodies. There are also celestial digital globes available. However, digital globes are not generally meant for commercial applications.

Virtual globes are also digital globes that can be viewed on the computer or any other interface. These may be simple globes used for classroom teaching, or they can be highly technologically advanced. Some virtual globes use state-of-the-art technology like satellite imaging and multiple GIS databases for real-time coverage. Virtual globes can be online or offline. These days, the application of virtual globes has become so common that they are also being fitted in cars in order to make navigation easier for the driver. They can provide detailed information, right down to a street’s name.

Another kind of digital globe is the hyperglobe that uses virtual reality to present spatial effects. These are used for visually depicting certain geographic processes and phenomenon such as the earth’s inclination, space travel, and satellite technology, through three-dimensional geoid visualization, animation, and real-time presentations. These also have interactive cartometric tools for making the data globally available.

Globes provides detailed information on Globes, World Globes, Digital Globes, Snow Globes and more. Globes is affiliated with Fiberglass Flagpoles.

Article Source: http://EzineArticles.com/?expert=Peter_Emerson

Interactive Mapping

By Joe Miller

Interactive mapping is a visual display medium which allows graphing, mapping, and even conversion to PDF of any type of information. This technology is used by national government agencies, airlines, chambers of commerce, ski resorts, and countless corporations to make information accessible and interactive to whomever they present the information.

Phone and credit card companies use interactive mapping to show billing information. Companies use it in reporting, forecasting, sales and marketing, and display retirement plan information to its employees, using Dashboard, PopChart, Optimap, and Highwire features for interactive and simple information presentation and utilization, even on a pocket PC.

What can Interactive Mapping Do for You?

Interactive mapping involves so much more that just maps. Dashboard, Popchart, Optimap, and Highwire provide interactive information in virtually any format: charts, graphs, pie charts, tables, etc.

In addition to the examples given above, here are additional ways to use interactive mapping.

Retail stores can track revenue, returns, and customer information across geographical demographics.

Manufacturers can track processing times along the supply chain.

Electric companies can track overall usage in geographic regions.

The CIA World Factbook collects and presents geographical, population, and even cell phone usage across the world with interactive mapping.

Airlines track cancellations, fares, purchases, flight loading, and seating.

Land developers find geographical survey of longitudes and latitudes for cities anywhere in the United States.

Businesses track receivables, payables, inventory, and sales.

Companies break down sales reports according to product.

Corporations publish stock reports.

Marketing statistical personnel create charts and graphs, using functions.

Doctors find cancer rates across the United States.

Consumers track orders and receipts.

Students view documents like the US Constitution, connecting to notes, comments, and references embedded in the text.

Is Interactive Mapping Technology Compatible with Other Technology?

Yes. Interactive mapping has found a way to work hand in hand with technologies companies already use. Interactive mapping is also adaptable to PDF. Some examples of technologies with which interactive mapping tools can interface include HTML, FLASH, EMF, WAR, and XML.

Business, government, and educational reports and informational presentations are constantly being created and published with a variety of technologies and applications already available on the market. Documents created with the same applications can be teamed up with interactive mapping tools to create a simple display of information with which companies and consumers alike can interact.

Article Source: http://EzineArticles.com/?expert=Joe_Miller

GIS Overview

Overview of GIS
Author : www.gisdevelopment.net

Introduction
Geographic Information System (GIS) is a computer based information system used to digitally represent and analyse the geographic features present on the Earth' surface and the events (non-spatial attributes linked to the geography under study) that taking place on it. The meaning to represent digitally is to convert analog (smooth line) into a digital form.

"Every object present on the Earth can be geo-referenced", is the fundamental key of associating any database to GIS. Here, term 'database' is a collection of information about things and their relationship to each other, and 'geo-referencing' refers to the location of a layer or coverage in space defined by the co-ordinate referencing system.

Work on GIS began in late 1950s, but first GIS software came only in late 1970s from the lab of the ESRI. Canada was the pioneer in the development of GIS as a result of innovations dating back to early 1960s. Much of the credit for the early development of GIS goes to Roger Tomilson. Evolution of GIS has transformed and revolutionized the ways in which planners, engineers, managers etc. conduct the database management and analysis.

Some Interesting Links :
What is GIS ?
A complete compilation of information on GIS
GIS guide to Good Practice
A brief introduction to GIS and Archaeology
An Introduction to GIS in Real Estate
Gil Castle's final draft of the real estate column appearing in Real Estate Issues, August 1995
A Brief Introduction to GIS Technology
Enhancing Community Capacity to use Spatial Information
Defining GIS
A GIS is an information system designed to work with data referenced by spatial / geographical coordinates. In other words, GIS is both a database system with specific capabilities for spatially referenced data as well as a set of operations for working with the data. It may also be considered as a higher order map.

GIS technology integrates common database operations such as query and statistical analysis with the unique visualization and geographic analysis benefits offered by maps. These abilities distinguish GIS from other information systems and make it valuable to a wide range of public and private enterprises for explaining events, predicting outcomes, and planning strategies. (ESRI)

A Geographic Information System is a computer based system which is used to digitally reproduce and analyse the feature present on earth surface and the events that take place on it. In the light of the fact that almost 70% of the data has geographical reference as it's denominator, it becomes imperative to underline the importance of a system which can represent the given data geographically.

A typical GIS can be understood by the help of various definitions given below:-
A geographic information system (GIS) is a computer-based tool for mapping and analyzing things that exist and events that happen on Earth
Burrough in 1986 defined GIS as, "Set of tools for collecting, storing, retrieving at will, transforming and displaying spatial data from the real world for a particular set of purposes"

Arnoff in 1989 defines GIS as, "a computer based system that provides four sets of
capabilities to handle geo-referenced data : data input data management (data storage and retrieval) manipulation and analysis data output. "

Hence GIS is looked upon as a tool to assist in decision-making and management of attributes that needs to be analysed spatially.

All About GIS

Test content7