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Re: LiDAR - US State High Points

Posted: Thu Dec 15, 2022 3:53 pm
by Eli Boardman
Yury wrote: Thu Dec 15, 2022 7:13 am Why should we care?
I like NY Adirondacks approach.
They defined their list of 46 highest peaks about a century ago and stick to it completely disregarding those new fancy gadgets like GPS and LIDAR.
This approach allowed them to define a list and avoid shooting a moving target.
Because the objective truth of mountain height, or high point location, doesn't cater to the whims of prior generations. A particular rock either is the high point, or it isn't. "When you play the game of [high points], you win or you die. There is no middle ground."

Re: LiDAR - US State High Points

Posted: Sat Dec 17, 2022 3:18 pm
by Candace66
Yury wrote: Thu Dec 15, 2022 7:13 am Why should we care?
I like NY Adirondacks approach.
They defined their list of 46 highest peaks about a century ago and stick to it completely disregarding those new fancy gadgets like GPS and LIDAR.
This approach allowed them to define a list and avoid shooting a moving target.
So it's just an arbitrary list of 46 peaks which may or may not be the highest. Yet they're calling it a list of the 46 highest. Have I got this right?

Re: LiDAR - US State High Points

Posted: Sun Dec 18, 2022 10:31 am
by Yury
Candace66 wrote: Sat Dec 17, 2022 3:18 pm So it's just an arbitrary list of 46 peaks which may or may not be the highest. Yet they're calling it a list of the 46 highest. Have I got this right?
No, it's not an arbitrary list.
It's a historical list of 4000ers in Adirondacks: https://adk46er.org/peaks/
Take a look at the 5 latest entries on this list.

Anyway, 4000 ft or 14000 ft is a rather arbitrary threshold, because it depends on rather arbitrary unit of measurements.

Re: LiDAR - US State High Points

Posted: Sun Dec 18, 2022 12:10 pm
by Ptglhs
And an arbitrary selection of sea level, which varies due to latitude, tide, temperature, time of year.

Re: LiDAR - US State High Points

Posted: Sun Dec 18, 2022 1:15 pm
by cougar
State borders are also arbitrary

Re: LiDAR - US State High Points

Posted: Sun Dec 18, 2022 4:26 pm
by Ptglhs
cougar wrote: Sun Dec 18, 2022 1:15 pm State borders are also arbitrary
Some Hawaiians would probably beg to differ with that. :D

Re: LiDAR - US State High Points

Posted: Sun Dec 18, 2022 4:29 pm
by greenonion
Ptglhs wrote: Sun Dec 18, 2022 4:26 pm
cougar wrote: Sun Dec 18, 2022 1:15 pm State borders are also arbitrary
Some Hawaiians would probably beg to differ with that. :D
Gotta give it to ya on that one. Good one!

Re: LiDAR - US State High Points

Posted: Sun Dec 18, 2022 8:01 pm
by donnyroush
I am a 48 state HP completer (or so I thought). Trying to decide what to do with this new information. Seems like I may need to revisit Pennsylvania. Might wait for more definitive evidence…and a trail.

Re: LiDAR - US State High Points

Posted: Tue Dec 20, 2022 4:46 pm
by ChrisinAZ
donnyroush wrote: Sun Dec 18, 2022 8:01 pm I am a 48 state HP completer (or so I thought). Trying to decide what to do with this new information. Seems like I may need to revisit Pennsylvania. Might wait for more definitive evidence…and a trail.
There probably won't be much more definitive evidence anytime soon--LiDAR has its limitations, and the thick vegetative growth around these candidates blocks LiDAR from getting a 100% clear ground read. That said, based on my experience extensively covering the north contour on Mt. Davis, and bushwhacking to just a single point in the south contour, the north has actual rock outcroppings whereas the south has very little in the way of rocks. I would probably call anyone who visited just the north contour and the traditional boulder at the tower and reached the coordinates of the apparent highest ground in that north contour as having made the top in terms of a good-faith effort. If you approach the north contour from the west, swing wide to the north, and approach it heading directly S, you will avoid a lot of the bushwhacking misery I put myself through!

Re: LiDAR - US State High Points

Posted: Thu Aug 22, 2024 9:04 am
by RyanSchilling
ChrisinAZ wrote: Thu Dec 08, 2022 3:15 pm (where I found a pair of sunglasses still sitting in the heavy brush, several feet off the ground, from a previous visitor!)
I saw this just now... you found my sunglasses :lol: They were steaming up as I fought the nasty rhododendrons two years ago. I hung them from my shirt, and they fell off at some point later. I made a fruitless effort to locate them before I gave up!

Re: LiDAR - US State High Points

Posted: Thu Aug 22, 2024 1:11 pm
by seannunn
Ptglhs wrote: Sun Dec 18, 2022 4:26 pm
cougar wrote: Sun Dec 18, 2022 1:15 pm State borders are also arbitrary
Some Hawaiians would probably beg to differ with that. :D
That's a good one Ptglhs. :mrgreen:

Sean Nunn

Re: LiDAR - US State High Points

Posted: Sat Sep 14, 2024 6:58 pm
by EricGilbertson
On Monday Sept 9 I brought a dGPS (spectra promark 220 with ashtech antenna) to Mt Davis and the northern and southern candidate PA highpoints that Lidar data measured higher. I took a 5hr measurement on the boulder, 2hr measurement on the northern candidate, and 2 hr measurement on the southern candidate. I processed data with OPUS and PPP.

I found that the traditional boulder summit is still the highpoint of PA.

Traditional boulder summit: 3213.3 ft +/- 0.2 ft
Davis North: 3210.0 ft +/- 0.1 ft
Davis South: 3209.8 ft +/- 0.1 ft

(NGVD29 datum, same as quad uses)

Detailed trip report with analysis here:
https://www.countryhighpoints.com/mt-da ... nt-survey/