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

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