Do You Really Need GPS
Posted by admin on March 29th, 2008 filed in gpstechstore
Throughout all time the big question has been and still is: Where in the heck am I?
Adam said, “Where are you going, Eve?”
Eve shook her blond hair and said, “Darned if I know, Adam. I’m just bored with this place.”
“Well, stay here then if you don’t know where you are going. You might get lost.”
Adam set on a rock and waited for her answer.
Eve said, “I won’t get lost, Adam. Besides, I’m not a man. If I do get lost, I’ll ask for directions.”
Adam said, “You must have some idea where you want to go, Eve. You can’t just go wondering off into the dark and dreary world.
She looked at Adam with her pale blue eyes and said, “I was thinking more of Paris than the dark and dreary world.
Back in those days folks tried to keep track of where they were by looking at the stars. The great explorer, Phendom, used the stars to navigate. In 45678 b.c. on his first trip to Greenland his chief navigator, Sogbottom, said, “I think we had better head back north, Phendom. I think that is the Southern Cross.”
I found only one reference to Phendom on Google.com. That is how unknown he is. The reference was cached, but the ever-loving Google.com said I could read the text if I liked. I decided to do that until one of those little boxes popped up and told me I would have to install the Korean Language module to read it.
That is how I learned that Phendom, who was probably the first Sea Explorer, was Korean.
I still remember three words in Korean from my Korean War days. I can say, “How are you? (awnyahasiminiga)” I can say, “Come here,” to a man (erioseeo). And I can call a dog (ereereereere, etc.). It’s best in Korea not to get the last two mixed up. Koreans like to throw rocks.
Back to the stars: If you measure the angle from the horizon to Polaris, you will know your latitude. Polaris is the “Pole Star.” You may know it as the “North Star.” To find Polaris, look for the big dipper. If you can’t find the Big Dipper, it is opposite the “W” which is also known as Cassiopeia. To see how this is all done go to: http://coolcosmos.ipac.caltech.edu/cosmic_kids/AskKids/northstar.shtml
You can see why I just love Google.com. “I love those goo goo googlely eyes!” You might try: http://pub2.bravenet.com/forum/167551711/show/337617 for more on Barney Google with the goo goo googlely eyes!”
Don’t forget to drop in to see Barney Google himnself at: http://www.toonopedia.com/google.htm. You will be glad you did.
At this point it would be proper to discuss how the early mariners determined longitude. Darned if I know how they did it. I do know that Captain James 1768-1780 A.D. was the first to use a chronometer to determine longitude. It says so at: http://en.wikipedia.org/wiki/Ocean_exploration.
The chronometer will just get us into a flimditty just as the sextant would. Let’s move on.
(I made up the word flimditty because it is just what we needed in that last sentence, right? You won’t find it in your dictionary or at Google.com. You must be thrilled to be reading the writings of a modern creative literary genious.)
There is no reason to get into a fitznizzle over longitude and the chronometer.
Skipping history, modern day navigators have a number of ways to find their way home. Some years back a friend of mine told me that he had bought a fishing boat at a sheriff’s sale for $800.00. He was very excited about that boat and so was I. He put a new V-8 engine in the boat and off we went fishing on Delaware Bay, God’s great gift to ardent fishermen.
My son and son-in-law tagged along and we cought a boodle of fish. Toward evening, I put my hand up to measure the altitude of the sun and I said, “In 40 minutes it will be dark. We’d better head in.”
Well, nobody wanted to quit fishing and my friend assured me that we would be able to get in by looking for the navigation light at the mouth of the Maurice River. We would follow the light and slip up the river to the dock.
Finally as the sun dropped into the abyse of spacetime my friend decided it was time to leave. He cranked up the engine but the boat didn’t move. Poking our heads to see what was below deck we found water. The boat had such a tonage of water that it would not move.
My friend had installed a pump so he flipped it on. That didn’t help, so we started bailing out the water. Eventually, we got the boat moving.
I suggested that we put on the lifejackets. The Delaware is full of ugly tankers and cargo ships and such. I could see us in the water screaming at the top of our lungs, HELP!
We headed east but we could not see the blasted navigational light. We moved south and finally we could see it. We motored up the river at a slow pace because the docks on the river had signs that said: NO WAKE!
We moved slower and slower as we took on more water. The musquitos got thicker and thicker. We thought we were with Bogey on the African Queen.
Finally, we arrived at the dock. That’s where we learned that we could not move to the dock because the boat would not steer properly. Then by luck on the 70th try, we pulled up to the dock.
I grabbed two five gallon cans of fish and ran for my Volkswagen bus, ten zillion mosquitoes helping me along.
The next morning, my friend went down to the dock to check on his bargain boat.
He couldn’t see it at first.
Then he found that it was only a few feet away.
Unfortunately, the direction was down!
Glub, glub!
Sorry for that major diversion from our very serious discussion on navigation and all.
Sometime after the compus was discovered, man discovered radio navigation. Transmitters along the cost sent out a characteristic bleep that boats could triangulate on or dead recon on to find their way home. We learn the following at: http://en.wikipedia.org/wiki/Radio_navigation
“The first system of radio navigation was the radio direction finder, or RDF. By tuning in a radio station and then using a directional antenna to find the direction to the broadcasting antenna, radio sources replaced the stars and planets of celestial navigation with a system that could be used in all weather and times of day. Taking two such measurements and plotting the directions on a map will result in an intersection, your current location. Commercial AM radio stations can be used for this task due to their long range and high power, but strings of low-power radio beacons were also set up specifically for this task. Early systems used a loop antenna that was rotated by hand to find the angle to the signal, while modern systems use a much more directional solenoid that is rotated rapidly by a motor, with electronics calculating the angle.”
Placing transmitters on Global Positioning Satellites solved all of our navigational problems except during heavy sunspot activity or overlyactive solarwinds.
The End
copyright©John T. Jones, Ph.D. 2005
John T. Jones, Ph.D. (tjbooks@hotmail.com)is a retired R&D engineer and VP of a Fortune 500 company. He is author of detective & western novels, nonfiction (business, scientific, engineering), poetry, etc. Former editor of international trade magazine. More info: http://www.tjbooks.com. Business web site: http://www.bookfindhelp.com (wealth-success books / flagpoles)
Tags: Adam and Eve, barney google, Delaware Bay, google, gps, GPS satellite, john t jones, navigationComment now »
GPS Usability Over Functionality
Posted by admin on March 27th, 2008 filed in gpstechstore
There is an easy test that I like to use when evaluating a GPS, or any type of electronic device. I call it the user manual test. When I pick up a new GPS for the first time, I see how easily I can operate the GPS with common sense alone and without using the manual. Criteria for a good GPS is firmly based on how easily I can operate the menu options and pick up the functions. This is an aspect that some people overlook yet it is perhaps the single most important part of a GPS.
The first reason that user friendly functions and menus are so important is that the vast majority of people who buy GPS units are seasonal or occasional users. They are not out there 5 days a week, honing their skills and keeping the idiosyncrasies of their GPS at the forefront of their mind! Consequently, most users want to be able to pick the damn thing up and be able to get their hands on accurate information that can make the difference between getting lost, or even a fatal ending to an outdoor adventure.
The second reason that GPS units need to be easy to use is that they are often used by groups such as hunters, fishermen and hikers. This makes it quite likely that some members of the group will not be experienced with your particular model or brand of GPS. In these kinds of circumstances it is doubtful that anyone will want to sit down and read a user manual, that is if you still know where it is! So do yourself a favor and get a GPS that makes sense to you without having to go to the book, if for nothing else that from a safety point of view.
The third reason it that if you are willing to spend a couple of bucks on your GPS and choose a top brand such as Magellan or Garmin you don’t need to worry too much about what functions are included. The level of competition between these two companies is so high that neither is willing to put sub-standard products into the marketplace. At http://www.thegpscentre.com you can see reviews of GPS units and see how close these brand really are in both quality and price. What will make the difference will be the users ability to take advantage of the functions.
Remember, there is no point having a GPS with several navigation screens, thousands of automatic way-points if you can’t work out how to use them with ease. Happy trails and safe navigating to you all.
The author is a regular contributor to http://www.incargpsworld.com and permission to reproduce this article is given only on the basis that all links remain active and intact.
Tags: camping, gps, hiking, navigationComment now »
GPS And How It Works
Posted by admin on March 26th, 2008 filed in gpstechstore
GPS stands for Global Positioning System, a satellite navigation system with twenty-four satellites in orbit. These satellites were put in place by the United States Department of Defense for military uses, and were called NAVSTAR. The first satellite was launched in 1978 and the twenty-fourth and last satellite was finally in place in 1994. In 1980 NAVSTAR was made available to the general public for commercial use.
GPS works 24 hours a day in any weather. The satellites orbit the earth twice a day in a specific orbit that is about 12,000 miles above us. In orbit, the satellites travel as fast as 7,000 miles an hour. As they are orbiting, they transmit information to receivers on earth. The receivers use this information to calculate the user’s location. This calculation is made by determining the difference between the time a transmission was made and when the receiver received it. This is then used to calculate the distance and the position is displayed on the receiver.
For a receiver to calculate a latitude and longitude position is to receive information from three satellites. To calculate latitude, longitude and altitude a receiver must be able to receive information from four or more satellites. After position is known the GPS can then tell the user information about speed, trip distance, the distance to a desired destination, sunrise and sunset times, bearing and other information.
While in orbit, the satellites are powered by solar energy. They also have backup batteries that are used in the event of no solar power such as an eclipse. The energy is used to power small rockets on the satellites that keep them in the proper orbit. At any one time only about 50 watts of power or less is used to transmit information. The satellites are designed to last about ten years, and the U.S. Department of Defense is constantly making and launching replacement satellites. Each satellite is about 2,000 pounds and seventeen feet across when the solar panels are out.
GPS receivers are generally accurate within 15 meters. Other than investing in a receiver there are no fees or other equipment required to access the GPS signal. If very accurate readings are needed, Differential Global Position Systems (DGPS) will provide accuracy within three to five meters. The United States Coast Guard operates the most popular DGPS.
Two power signals are transmitted and are referred to as L1 and L2. The L1 frequency is used for civilian purposes. These signals are relatively low power signals and travel by line of sight, so they can go through clouds, glass, and plastic, but not solid objects like buildings or mountains. In every transmission the satellite sends three types of information, its pseudorandom code, ephemeris data and almanac data. The pseudorandom code is an I.S. code that identifies which satellite the information is being sent from. Ephemeris data tells the receiver where the satellite should be at any time of the day, and almanac data sends information about the status of the satellite, the current date and the time. The almanac data is the part that is essential for determining the user’s position.
Chris Simons is a prolific freelance writer. You are welcomed to visit http://gps.theconsumerguide.net, for more information on GPS units and tracking systems.
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