“Smart Map is a very detailed survey of every feature of the golf course — every tee, green, fairway, and sandtrap,” says Richard Beckmann of Skylinks. “Our position is then associated into the map and we know where we are relative to everything else around us.” As the golfer finishes at one hole, the Smart Map program is triggered to give you in- formation about the next hole that you’re playing. Every cart is monitored from the club- house using an RF radio link. Called Skyranger, it allows the manager to keep a close eye on the vital speed of play on the course. “We can go in and take a closer look at a few holes and take a look at exactly what’s going on,” says Beckmann. “Red cars indicate that there’s some sort of problem that the pro-shop manager would like to be aware of. So, if we go to the alarm screen, for example, we can dictate which cars we want to take action on.
The US Department of Defense developed the GPS system for the purposes of accurate navigation and positioning. It consists of both satellites and ground receivers, each of which perform well-defined functions. Four satellites must be used in order to determine the position of one ground receiver. The first three satellites are used to determine the position relatively accurately, and the fourth is used to synchronize the time clock of the receiver with the extremely accurate atomic clocks of the satellites. There are other measurement errors that come into play, but all may be quite accurately corrected for using various methods. In fact, the US Department of Defense purposely incorporates some “noise” into the system (which it is later able to decrypt) to prevent potential enemies from using GPS to develop their own weapons. GPS time keeping is used to set the clocks that regulate international communications and computer networks. These GPS clocks are used in banking for money transfers and bank time locks, among other things. They are also used for time keeping in certain scientific experiments. Most of the GPS manufacturers are not explicit about what kind of problems non- compliant GPS receivers will experience at the time of the roll over. Some of the problems could be:
1: The GPS receiver may not be able to locate the GPS satellites. In this case the receiver will not work at all. 2: The receiver may take a longer time than usual, possibly up to two hours, to locate the satellites. Having found the satellites it may or may not display accurate dates, times or positions. 3: The receiver may display an accurate position but the date could be as much as 19 or 20 years in error. 4: The receiver may display a position that is not correct. There have also been suggestions that particular problems will exist for some receivers during week 0, but that following week 0 they will operate normally. The GPS clocks will face the same kinds of problems with respect to dates and time.
The future of GPS is as unlimited as your imagination. New applications will continue to be created as the technology evolves. The GPS satellites, like handmade stars in the sky, will be guiding you well into the 21st century
1. Thompson, Steven D. An Introduction to GPS, (Every Man’s Guide To Satellite Navigation). ARINC Research Corporation, 1994
2. “The Untold Story of CALCM: The Secret Weapon Used In The Gulf War”.
3. GPS World January 1998, Page 17
4. Dana, Peter H. GPS Users Overview. Available on-line at www.utexas.edu/dept/grg/gcraft/notes/gps/gps
5. Available information on-line at the United States Coastguard Navigation Center
6. GPS Joint Program office. ICD-GPS-200: GPS Interface Control Document. ARINC Research Corporation