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.
