Myths about golf GPS…
GPS companies routinely claim 1-3 yard accuracy
It's a common theme in their advertising. Unfortunately for them, it is simply NOT TRUE! The experts will tell you that the Handheld GPS accuracy of a distance to a given point can be expected to be +/- 7 yards 95% of the time. The GPS technology "estimates" yardages based on a number of different factors. This means that a 75-yard shot to the middle of the green could range from 68 yards to 82 yards. A 300-yard shot would be within 293 and 307 yards. In other words, the shorter the distance, the less useful the GPS technology.
Laser technology is just the opposite. The 75-yard laser measurement would be between 74 and 76 yards 98% of the time while the 300-yard measurement would be between 297 and 303 yards 98% of the time.
It's simple, GPS cannot estimate distance to the pin
Only to stationary landmarks, such as the front, middle, and back of the green. Some cart-mounted GPS claims the ability to estimate distance to the pin, but in reality they are only measuring to section of the green where the pin is located. So, if the pin is not located in this section (because the hole was cut in the wrong spot), you will not receive distance to the flagstick estimations.
Only if they didn't care about accuracy
Contrary to what you see in paid advertisements, NO professional player in the world is using GPS to prepare for tournaments. Why? Top players do not use GPS to map golf courses because of the inaccuracy of the measurements. With that kind of money and prestige on the line, distance estimates to within 8-10 yards aren't good enough. If they were, you'd never see a caddie out walking a golf course prior to a tournament; they would just use the GPS to map the course. What you see on TV are paid endorsers telling you the company line.
In fact, it's NOT enabled most of the time
WAAS (Wide Area Augmentation System) is only available in North America, and it was designed to support high-precision GPS navigation of aircraft, not on-the-ground uses that can have significant problems with ground-level obstructions. There must be line-of-sight between a WAAS-enabled GPS receiver and at least one of the WAAS satellites. Across the United States, WAAS satellites are in the southern sky and range in altitude from 10' to 55' above the horizon. Tree canopies and other obstructions that block this part of the sky prevent GPS devices from receiving WAAS corrections. The golf GPS companies could put indicator lights on their units to let you know when WAAS is functioning. Why don't they? Because you'd learn that it is not functioning more often than it is.
Laser wins the speed battle any day
One of the arguments heard in favor of GPS is that you don't have to touch it like you do a laser rangefinder, which has to be picked up and fired for each shot (seems like a small price to pay for information that is accurate and useful). I think what they forget is:
- Course Downloads - take it home, plug it in, go to the website, find the course?
- Recharging - take it home every night to plug it in. Wouldn't you like to just leave it in your bag? Well, you can't.
Odds are the sprinkler head markings are correct
Your GPS is giving you the wrong measurement. As you read through this site, you'll see that it is common to get GPS readings that are off by 7 or more yards. And keep this in mind - if you find that every sprinkler head on the course is incorrect, don't you have to question the tool you are using to "check" those measurements?
If you want to check sprinkler heads, use a laser. It's simple, fast, easy, and, most importantly, accurate.