My GPS is lying

[Alan Clifford]

Was in the car park and my gps told me the the distance to the middle, front and back of the 9th green. It said that the back was furthest away.

Wrong.

The car park is behind the 9th green.

So what the device seems to be doing is using one location point, presumably for the middle and adding on some yards for the back and taking some off for the front.

Not really a problem but the information it describes it is giving is not the information you get.

 

[YandaB]

Ive always assumed that it meant front and back from where I've been standing. So in your case the "back" that it was referring to was actually the real front so "correctly" furthest away.

Edit: My reasoning for this is that if I've ever been to one side of a green, I've never seen all 3 numbers the same. The "front" is always nearest to me at that point.

 

[sunshine]

My Garmin watch has a little diagram of the green with the 3 spots marked on the diagram showing front / middle / back. Those 3 spots are fixed, so the GPS will always measure from where I am standing to those 3 spots.

I've never looked at my watch from behind the green to see if it reverses the order.

EDIT:

My comment above is rubbish.

I played a few holes this evening and paid attention to my watch. The gps must have the perimeter of the green marked out, because as I walked around the green the 3 red dots representing front/middle/back rotated around the green to always show me the front relative to my position.

 

[LincolnShep]

It's telling you Front/Middle/Back relative to your position. "Back" is the bit of the green that is furthest away from you, "Front" is the closest bit. This seems a lot more useful than having fixed points, especially if you're side on to the green.

 

[JayB]

As stated, the front of the green is always in relation to where you are stood, why on earth would it be any other way? It would just cause confusion.

 

[Alan Clifford]

Ive always assumed that it meant front and back from where I've been standing. So in your case the "back" that it was referring to was actually the real front so "correctly" furthest away.

Edit: My reasoning for this is that if I've ever been to one side of a green, I've never seen all 3 numbers the same. The "front" is always nearest to me at that point.

I'll do some research to see if the difference between the middle and the back and the middle and the front stay constant. On a long, narrow green they should change when moving around the green if 3 gps points are used.

 

[jim8flog]

Is the car park not OB where you play.

 

[Alan Clifford]

Is the car park not OB where you play.

I only noticed because I accidentally pressed the button and it spoke to me.

 

[Jimaroid]

What madness is this?

It’s giving you the points of a line intersecting the green through it’s mean centre from where you’re observing? I can’t imagine it ever being fixed points and if it was I’d throw that GPS device away.

The map data is all just a collection of polygons. The centre of a polygon is easy to calculate, so it’s just like the below example to illustrate. The red circles nearest and farthest from where you’re standing at any end of the of the blue lines drawn through the mean centre C.

 

[Alan Clifford]

What madness is this?

It’s giving you the points of a line intersecting the green through it’s mean centre from where you’re observing? I can’t imagine it ever being fixed points and if it was I’d throw that GPS device away.

The map data is all just a collection of polygons. The centre of a polygon is easy to calculate, so it’s just like the below example to illustrate. The red circles nearest and farthest from where you’re standing at any end of the of the blue lines drawn through the mean centre C.

View attachment 49521

I hope you are right and that I am an idiot