My adventures in measuring distance (and other musings)

[Steve West]

... I've come up way short on holes by trusting the signs and throwing the wrong disc.

Thanks, I needed a fresh excuse for why all my throws are short. All my old excuses are getting worn out.

 

[@CD-]

Consistently following uDisc recommendations here will give good enough results to compare throws & measure improvement
https://udisc.com/blog/post/udisc-tips-accurately-measure-throws

• throw from a landmark visible on the map, setting the blue dot to the starting spot makes the +/- accuracy irrelevant. I like using the dirt corner of baseball infield since they are usually well defined on all maps.
• wait for more satellites to narrow position (+/- 13ft is the best)
• trees/buildings limit the triangulation
• may take 30s to fully start up the phone GPS (conserving battery)

its unlikely the GPS uDisc course maps in wooded situations are accurate distances so laser would be better for those.

 

[BillFleming]

Consistently following uDisc recommendations here will give good enough results to compare throws & measure improvement
https://udisc.com/blog/post/udisc-tips-accurately-measure-throws

• throw from a landmark visible on the map, setting the blue dot to the starting spot makes the +/- accuracy irrelevant. I like using the dirt corner of baseball infield since they are usually well defined on all maps.
• wait for more satellites to narrow position (+/- 13ft is the best)
• trees/buildings limit the triangulation
• may take 30s to fully start up the phone GPS (conserving battery)

its unlikely the GPS uDisc course maps in wooded situations are accurate distances so laser would be better for those.

Yeah, but +/-13 feet can mean the measurement is off by 26 feet (off by 13 feet at the starting point and off by 13 feet at the end point) so your distance can be anywhere from 26 feet shorter than uDisc says or 26 feet longer (or anywhere in between). I've talked to some uDisc users who think the +/- number is how inaccurate the final measurement is...they didn't realize it was the accuracy of the current location and that uDisc was saying they were currently somewhere in a +/-13 (or whatever) radius circle of where uDisc thinks they are.

 

[davetherocketguy]

And that's assuming the +/- the app is giving you is correct. I'll bet it's much worse - and that's not the fault of UDisc. UDisc is just getting that info from elsewhere.

 

[@CD-]

Just trying to pass on UDisc's blog information for getting the most accurate results consistently.

The single most important thing is the blue dot on the map. The center of the dot represents the exact point UDisc will measure from while the halo surrounding it represents how wrong your phone thinks the dot could be. By using your eyes and looking around, you can figure out if the blue dot is exactly where you're standing. If it is, you can safely ignore the margin of error displayed on your screen. The blue dot is the only thing that matters.

So if enough landmarks are present on the map at the practice field or on the course you can pinpoint the starting and ending points to narrow the GPS inaccuracy at each like measuring distances using Google Maps.

OP seems to have some issue with the measurements taken by rangefinder even if they match the UDisc phone GPS. Rangefinder probably was shooting short and targeting something else. The wheel measurement is likely the least accurate/consistent out of all of three options tried.

 

[itsRudy]

At some point in the last year, I bought a rangefinder, the Apex piece off Infinite Discs. It was fun to play with, but I found it difficult to get repeatable results. I'd throw a shot on a soccer field, pull up uDisc, walk out to my shot, uDisc would read 280, then I'd use the rangefinder to measure the distance to my stuff. And I'd bring up something like 226 feet, then click the button and after a few clicks start getting 280.

...
...
...

I had a $10 gift card that was about to expire, so I go buy a measuring wheel yesterday from Harbor Freight. I take it out to my practice spot. It is wet and getting dark, but I just wanted to confirm what I was throwing yesterday. I walk it out with the wheel and it measures about 220 to 230 feet. What?!?!?!?!?! I get 270'ish with uDisc. I have my discs, so I throw some shots. I'd already made my first form change and was getting more distance than the day before. Measured out to about 285 on uDisc and 236 to 240 with the wheel.

Ditch the gadgets. Know your stride length.

Go out to a field at least 200' long, longer maybe. Either known markers measured in google maps or with your measuring wheel.

Start walking normally, don't worry about missteps it will average out if you go across a few times. I start with my left leg and everytime my right comes down, that's another stride. Count your strides. Go up and down the field at least 4x.

(field length x times across field) / strides = stride length.

Example (200 ft long x 5 times across) / 250 strides = 4 ft stride.

I have pretty short legs, I found my exact stride is 4 ft on the dot. Last week, I threw a disc that had to fight a lot of forest and wondered how far and used Udisc and counted my strides. 48 strides, 192 ft, app and the stride method agreed on the dot.

Except strides don't need extra gear, batteries, or slowing yous down. The wait time on even Udisc to get GPS zoned in is a PITA. It has been pretty damn consistent for me over the years, even on normal elevation (steep is another story).

 

[davetherocketguy]

I have pretty short legs, I found my exact stride is 4 ft on the dot.

4'? Are you sure? Most places I've seen indicate average stride length for "short" folks are around 25-29". I think you ought to take your own advice and ditch the gadget and get a really long tape to measure your stride length. Maybe I'm wrong but I don't think 48" per stride sounds right.

Here's a good link on smart phone GPS from the experts. +/- 16' in good conditions and it gets WORSE from there - especially around trees. And where do we play a lot of disc golf? In the woods? Again, how accurate do you want to be? 32' off or worse ok? Think about it, the putting circle is 32'10"

GPS on your phone is great for navigation but for this stuff its pretty terrible. But some of you seem pretty dead set on using them for this so if you're happy with being that far off I don't care...

 

[autocrosscrx]

I've done the stride thing plenty. And I've found it unreliable. It might be 102 strides to walk out to a disc, then 98 strides to walk back. It rarely takes me the same number of steps to walk to my shot as it takes to walk back.

Probably more important than that is that I absolutely hate counting steps. The absolute last thing I want to do after a 10 hour shift of walking around and counting things is to go out in a field and count steps.

 

[Martin Dewgarita]

4'? Are you sure? Most places I've seen indicate average stride length for "short" folks are around 25-29". I think you ought to take your own advice and ditch the gadget and get a really long tape to measure your stride length. Maybe I'm wrong but I don't think 48" per stride sounds right.

It's interesting to me how many people advocate pacing as an accurate measurement. 10 years ago you can find me advocating pacing and how accurate it can be, and I swear everyone thought I was nuts..

I think the confusion here is definition/interpretation of stride/step/pace etc. 4' is likely a single "step" or "pace" which might mean different things depending on where you learned them, or how you interpret them - but in my mind it is the distance from where the left foot leaves the ground to where the left foot touches the ground again. 4' is quite short, I have a relatively short pace, and mine is (at least last time I measured) exactly 5', meaning a 2.5' (30") single stride (from left foot to right foot).

As has been mentioned, many folks that measure pacing will count every time one foot touches the ground (left foot in this example). A 5' pace certainly makes measuring pretty easy, and is quite accurate when practiced.

 

[itsRudy]

4'? Are you sure? Most places I've seen indicate average stride length for "short" folks are around 25-29". I think you ought to take your own advice and ditch the gadget and get a really long tape to measure your stride length. Maybe I'm wrong but I don't think 48" per stride sounds right.

It's for 2 steps. I was explicit in my post.

"I start with my left leg and everytime my right comes down, that's another stride."