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GPS system saves time and frustration
July 30, 2012
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by Mark Ollig

“Do you want the portable GPS system added?” asked the person across the counter from the Avis Car Rental.

With a bit of hesitation, I said, “Yes.”

Why the hesitation? Well, here’s the scoop: This tech writer has never used a Global Positioning Satellite (GPS) system before.

The Avis representative then handed me a small case with the GPS receiving device inside.

I proceeded to my rental car – which provided me with another “first.”

Looking closely at the steering wheel column and dashboard, I exclaimed, “Where do I put the key in?”

There was no ignition key slot.

I glanced down at the keychain the Avis representative gave to me and realized there was no car key on it.

This car used the futuristic Jetson’s “push-to-start” button.

After yours truly figured out how to start the car, he removed the Garmin GPS device from its case and plugged it into the car cigarette lighter socket, where it booted up to become functional.

“Enter a destination,” said the GPS internal speaker.

Yes, the thing talks.

This particular GPS device accepts typing in an address via its touch-sensitive screen.

A user can also select an icon from the Garmin GPS menu for finding the nearest restaurant, gas station, or in my situation; lodging.

After verifying the address of my hotel destination, the highway route I would be traveling was displayed on the Garmin GPS screen.

Then, in HAL-like fashion, the GPS instructed me to buckle my seatbelt.

While driving, the GPS would audibly inform me when to make turns, which lane I should be in, and the distance to my destination.

I followed its verbal directions and watched the screen displaying the small blue arrow (my car) traveling along the projected highway route.

“This is much better than trying to follow a roadmap, or stopping for directions,” I thought to myself.

The GPS informed me to turn left. I had arrived at the Embassy Suites with no frustrations, and, by following the GPS route instructions, I saved time.

Most of us already know the GPS system had its beginnings with the military, and that the GPS receiving units on earth are in contact with orbiting satellites.

I was reading a paper off of the University of Florida website which provided me with some background on the US GPS system.

The launch of the Soviets Sputnik I, in 1957, may have inspired the first use of a satellite for location navigation.

During this time, researchers at John Hopkins Applied Physics in Baltimore reasoned since they knew their exact location on the earth, they could determine the exact location of the Sputnik satellite by measuring the radio frequency shifts that Sputnik transmitted towards the earth as it approached and moved away from their location.

This discovery led to the conclusion that one could determine their position on the earth as long as one knew the precise position of an orbiting satellite.

During the 1960s, the US military secretly worked on and tested various satellite navigation systems.

To make a GPS system a reality, improvements were made, not only in existing materials, electronics, and technology, but in the development of atomic clocks – as accurate time-keeping is critical because the GPS system is dependent upon the signals from the receivers on the ground, to the earth-orbiting satellites in order to establish location.

Each satellite has its own atomic clock.

In 1973, an estimated 24 Navigation System using Timing And Ranging (NAVSTAR) satellites were planned to provide latitude, longitude, altitude, direction of travel, travel velocity, and correct time of day.

In 1978, the first NAVSTAR satellite was launched into earth orbit at an altitude of 12,625 miles.

NAVSTAR is a project of the US Defense Department. Its Control Center is at the US Air Force Space Command, Falcon Air Force Base, Colorado Springs, CO.

The NAVSTAR GPS system consists of three segments: space, control, and user.

Space, of course, is where the NAVSTAR earth-orbiting satellites are located.

Five satellite monitoring stations on earth make up the control segment. They are located in Hawaii, Kwajalein, Ascension Island, Diego Garcia, and Colorado Springs.

Three ground antennas are located at Ascension Island, Diego Garcia, and Kwajalein.

There is a Master Control Station (MCS) in Colorado, located at the Schriever Air Force Base.

The user segment includes the GPS receiving devices antennas and processors, which provides the end users with positioning, precise timing, and velocity information.

The newest GPS satellite to be launched into orbit is called the NAVSTAR 66; it was launched July 16, 2011.

This satellite replaces the 20-year-old NAVSTAR GPS 2A-11, which was launched from Cape Canaveral atop a Delta 2 rocket July 3, 1991.

Of the total NAVSTAR satellites, three are operating as “working spares.”

Using NAVSTAR, any location on Earth is viewable by the orbiting satellites at all times, so driving directions and user locations are computed instantaneously.

The NAVSTAR GPS service is available to anyone anywhere, day or night, and provides service in all weather conditions.

Any of the NAVSTAR satellites (and most other earth-orbiting satellites) can be tracked in real-time at: http://www.n2yo.com.

After successfully using the GPS to find my way around southern Florida, I realized how indispensable a GPS is. So, yours truly has decided to get a GPS receiver either as an app on my Android mobile device, or, as a portable device I can keep in the car.

I will probably end up recycling my paper highway roadmaps – if I can find them.


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