GPS Accuracy

[DannyG]

I was a real Golfshot fan but lately the gps readings have been all over the place. I walk on a tee and get a totally different reading from the lasered marker in the ground. If I walk away a few yards and then come back I'll get a different reading. I just don't trust it anymore.

[Fourputt]

Originally Posted by DannyG

I was a real Golfshot fan but lately the gps readings have been all over the place. I walk on a tee and get a totally different reading from the lasered marker in the ground. If I walk away a few yards and then come back I'll get a different reading. I just don't trust it anymore.

That is a problem with your specific receiver, not with the technology as a whole.  There is something broken in your unit.  Don't know what recourse you have (warranty, etc.), but it needs repair or replacement.

[Dad-2-3]

Originally Posted by DannyG

I was a real Golfshot fan but lately the gps readings have been all over the place. I walk on a tee and get a totally different reading from the lasered marker in the ground. If I walk away a few yards and then come back I'll get a different reading. I just don't trust it anymore.

Golfshot has been dead nuts for me. I recently played at a course in Idaho which had tons of tall evergreens, and my IPhone 3gs matched my brother's $400 laser rangefinder. At the most there was 2 yards difference. not too bad for a FREE app!

[FieldStriper]

Probably the most important function of a golf GPS is its' accuracy then its' ease of use.

To judge its' shot distance accuracy, I laid out two 300' tape measures end to end (200 yds) and further broke that down to every 25 yds. I gave each distance 30 secs prior to recording the number to give the gps time to adjust to my movements. I ran the experiment 3 times.

The following 25yd increments were recorded as follows:

25-(28,26,22)
50-(54,49,46)
75-(78,73,73)
100-(102,99,100)
125-(127,125,125)
150-(151,151,149)
175-(178,173,175)
200-(204,200,201)

So as you can see, even the Bushnell Lasers are only accurate to +/- 1 yd. For the extra $250 they want for it, I decided to buy the watch and spend the extra $250 on a new driver. The watch appears to be more accurate the longer the distance. I found it very easy to use and won't miss having to put the laser up to my eye, hold it very steady to make any more measurements. I am not a good enough golfer that 1 or 2 yds is going to make a big difference in my score.

Enjoy

[David in FL]

This is an OLD thread, but GPS couldn't care less "how far" the distance is. It simply identifies your position against a formerly plotted position. Civilian GPS is accurate to about 3 meters....10 feet.

[Rulesman]

How accurate is GPS?

Today's GPS receivers are extremely accurate, thanks to their parallel multi-channel design. Garmin's 12 parallel channel receivers are quick to lock onto satellites when first turned on and they maintain strong locks, even in dense foliage or urban settings with tall buildings. Certain atmospheric factors and other sources of error can affect the accuracy of GPS receivers. Garmin® GPS receivers are accurate to within 15 meters on average.

Accuracy Values by Garmin Receivers

Accuracy of position determination

The declaration of the accuracy by Garmin GPS receivers often leads to confusion. What does it mean if the receiver states an accuracy of 4 m? This readout refers to the so-called 50 % CEP (Circular Error Probable). This means that 50 % of all measurements are within a radius of 4 m. On the other hand, 50 % of all measured positions are outside of this radius. Furthermore, 95 % of all measured positions are within a circle of twice this radius and 98.9 % of all positions are within a circle of 2.55 the radius.

In the given example , nearly all positions are within circle with a radius of 10 m. The determined position is in the worst case accurate to 10 m.

. Newer Garmin GPS receivers with WAAS (Wide Area Augmentation System) capability can improve accuracy to less than three meters on average. No additional equipment or fees are required to take advantage of WAAS. Users can also get better accuracy with Differential GPS (DGPS), which corrects GPS signals to within an average of three to five meters. The U.S. Coast Guard operates the most common DGPS correction service. This system consists of a network of towers that receive GPS signals and transmit a corrected signal by beacon transmitters. In order to get the corrected signal, users must have a differential beacon receiver and beacon antenna in addition to their GPS.