Garmin Course Measurements

[mikejohnchapman]

A group of us were out on a course today and as it happened we were all wearing Garmin watches.

It was somewhat surprising there was a +/- 5 yard difference in the yardages displayed when we stood together on the same hole. I assumed the difference related to which satellite the different watches picked up - is this correct?

I also assumed it picked up a straight line distance to the centre of the green. When playing a dog leg hole one of my partners insisted it calculated the distance based on the shape of the hole. His logic was the course map was downloaded into the watch so the distance was calculated via the elbow in the dog leg. He speculated they were taken from the course measurement certificates and hence followed the measured shape. I didn't see how this would work - was I right?

 

[GreiginFife]

Not sure of method, but my mate’s Garmin watch is consistently 5-8 yards different to my Skycaddie watch. The Skycaddie is using ground mapped data.

 

[FuzzyDuck]

Every device I have used definitely uses the straight-line distance to the hole. The 7th at Puttenham is a good example, the card says hole is 450+ yards, watch says 370 or so.

 

[wjemather]

GPS gives straight line distances.
Differences in distances given by different devices, even from the same manufacturer, can be for many reasons, including: hardware differences (especially the GPS itself), software/firmware and course maps, the specific satellites picked up, etc.

 

[sjw]

GPS accuracy is measured in +/- feet as well. I think it's 10, 15 feet? I can envisage a 5y difference being easily possible

 

[Jigger]

There’s a similar discrepancy between my gramin and my Arcoss. Generally 5yards variance is more than my swing variance so it’s nothing to worry about. I’ve a laser range finder too and the garmin is never far off

GPS is definitely line of sight which is why the map on the higher end is useful.

 

[jim8flog]

Garmin say

With a strong satellite signal, the GPS position reported by an outdoor watch should be accurate to 3 meters or 10 feet. A weaker satellite signal may ...

So if you all say the same thing you could be wrong anyway.

 

[HomerJSimpson]

My Garmin and laser are usually on;y +/- 2 yards apart but the yardages on my M5 trlley can be more than 10 yards out from both. Don't know why as it picks the right course when logging into the trolley and it can't be looking at anything different. Will be interesting to see what happens next time I play an away course

 

[harpo_72]

After reading this thread I used the Garmin and laser yesterday. I would say the discrepancy was minimal and the laser as always gives you a precise position- but talent to hit that precise position is still the major Achilles heal of all of this.
I have since updated the garmin data with clubs but I never really understood the benefits because it’s so dependent on the day and you have to dial in for the conditions and yourself.

 

[SteveJay]

Further to earlier comments, read a while back that non military GPS equipment is only going to be accurate to within about 5 yards. I know that my usual playing partners often have slightly different yardages showing on their watches, even if they are the same brand.

 

[sunshine]

When playing a dog leg hole one of my partners insisted it calculated the distance based on the shape of the hole. His logic was the course map was downloaded into the watch so the distance was calculated via the elbow in the dog leg. He speculated they were taken from the course measurement certificates and hence followed the measured shape.

Classic example of golfers bullshititis. Seriously affects many male golfers. See threads on knowledge of rules of golf, driver distances etc

 

[sunshine]

My Garmin and laser are usually on;y +/- 2 yards apart but the yardages on my M5 trlley can be more than 10 yards out from both. Don't know why as it picks the right course when logging into the trolley and it can't be looking at anything different. Will be interesting to see what happens next time I play an away course

How are you able to compare accuracy of laser to Garmin? What are you measuring to get +/- 2 yards?

 

[harpo_72]

How are you able to compare accuracy of laser to Garmin? What are you measuring to get +/- 2 yards?

That’s a good question because the sat nav only uses fixed points of front middle and back .. a laser is the flag/head of the slow player ahead/ or the tree at the back … and yes when I laser heads I do make silenced gun noises .. childish possibly, but what else do you do when bored of waiting watching some idiot go through aim point twice on a straight putt that’s 2ft away and for a double bogey or more ?!?

 

[sunshine]

That’s a good question because the sat nav only uses fixed points of front middle and back .. a laser is the flag/head of the slow player ahead/ or the tree at the back … and yes when I laser heads I do make silenced gun noises .. childish possibly, but what else do you do when bored of waiting watching some idiot go through aim point twice on a straight putt that’s 2ft away and for a double bogey or more ?!?

I know I'm going to do this from now on. Sniper double tap to the head