MacNaughton Mountain Adirondacks*** ELEVATION CALCULATION...

[dom15931]

Results of the "ALL CAPS" at the end.

Having completed all 46 and knowing the story behind the "fallen four" and the mystery surrounding MacNaughton mountain and the lack of a clear and modern method, to my knowledge, of a measure of it's true elevation, on May 29th 2016 I set out to A. Conquer the peak, and, B. Take high-accuracy RTK GPS measurements of the summit elevation which results I intend to present to the NGS/USGS for review and hopefully a field verification.

I left the ADK Loj Visitors Center parking lot at a late but well rested 10:30am. I would have good luck with the weather all day encountering no local impacts of thunderstorms. It was hot though, but not quite as bad as the day before and the nearby storms would cool things off. I arrived at Rocky Falls to still sunny weather with only a handful of people, unlike the previous day in the Mac's which was like a Black Friday at the mall of sorts with it crowds, enough so that I was probably one of ten people to do the Shepard's Tooth that day. Ahhh... Much less people. The conditions on the trail were dry and I was leisurely going about 1.8 miles an hour or so, breaks included, through this and the first half of the trail to Wallface Ponds. I didn't want to rush in the heat as it just exponentially increases water consumption with the unusually high temperatures.

The second half of the trail to Wallface Ponds...ugh...what a mess. It was slow going while trying not to sink to my knees in mud. Most heard paths are better maintained even if naturally. It a series of long-untrimmed pathways and stretches of swampy bogs that can, and on the way back did, send you in circles! A light, but pleasant rain was falling and had been for a light while. Thunder rumbled in the distance all around me, but today the mountain gods were on my side it would seem.

I never found a clear heard path at the base of the mountain and did not search too hard. I just aimed for a compass bearing nearing the center of the ridge as the gain amount isn't too bad. Man did I luck out as going up I had a pleasant and very not technical route up the mountain. No huffing and puffing or obstacles to deal with. I arrived at the summit ridge not knowing my location. The GPS I had on me was packed safely away and was not being used at any point monitor my traveling locations. I walked out to the far side of the ridge, not knowing if I had walked by the summit and then headed back to find the summit sign. I looked at the cellular devices I had on me. Net10 had a decent internet connection. Verizon was in and out. T-Mobile had a reliably steady 4G connection.

"4G MacNaugton on my smart phone, now how cool is that?"

Really cool, actually, but not for surfin the web, messaging friends or social media posting!

A cellular network with internet can be used to dial in and create a Virtual-Reference-Station (VRS) in the absence of a physical base station with the proper equipment. This allows for Real Time Kinematic corrections of about two dozen potential satellites with these types of GPS. You may see these setups on survey crews laying out roadway construction points or controlling large equipment. I am not up here with a hand-held unit, but the type of setup the USGS would use to do the same.

While on my walk out I screwed up not once but twice, first by poorly and arrogantly descending without watching my bearing causing an unnecessary southward decent and 500' drop and then later understandably struggling in the bogs and spinning circles for an hour in the dark one thing made the travel easier and worth the struggle was that:

On the summit I repeatedly observed the same result of the output from the GPS at both the summit sign and the assumed summit rock nearby averaging approx 180 RTK "FIXED" readings each:

NYSP East NAD 83 CONUS NAVD 88 Geoid 12(A) Elevation=

4004.4137,Summit Sign
4004.3118,Summit Sign Check
4004.3096,Summit Sign Check
4004.4218,Summit Sign Check
4005.4922,Summit Rock
4005.2703,Summit Rock Check
4005.3035,Summit Rock Check
4005.3349,Summit Rock Check

All positions max VRMS of 0.3', or 4 inches, allowed into averaging. The same result was re-calcuated, statistically, at each location each time. Google Earth's terrain model was what made me choose to check MacNaughton (it has the summit around 4014') along long with the known errors in the region. In short, there was reason to believe that it was actually over 4,000.

The work is in process of being submitted to the appropriate agencies for review, comment.

4 may have fallen, but hopefully ONE will be raised.

-Dom

 

[Trail Boss]

Questions for you:

When you say "summit rock" do you mean the viewpoint on a rock-ledge located on the eastern "bump". The sign is located on the western bump. There's about 800 feet of herd-path between the two spots.

What is the make and model of the equipment used?

Has the equipment been calibrated?

What service was used to establish the VRS?

 

[dom15931]

Questions for you:

When you say "summit rock" do you mean the viewpoint on a rock-ledge located on the eastern "bump". The sign is located on the western bump. There's about 800 feet of herd-path between the two spots.

What is the make and model of the equipment used?

Has the equipment been calibrated?

What service was used to establish the VRS?

By "summit rock" I mean the place, near the sign (say 10' away) and slightly higher, of solid ground and open rock where a monument could be set. This summit is difficult to establish as it's "exact" point could require topography as the ridge "bumps" a bit, but I agree that the vicinity of the sign is the highest area. I took a reading at the lookout you have shown and found the ELEV here to be approx 3998'.

I have sent you a PM with further details on equipment specs, etc.

 

[Trail Boss]

Thanks for the information, I appreciate it!

 

[JoeCedar]

You have demonstrated the precision of the measurement, but isn't the real question the accuracy? There must be many assumptions in creating the mathematical model which does the calculations. This is a difference of only 0.1% to a model position of sea level. Has the model been thoroughly validated? Is the result accurate?

 

[dom15931]

You have demonstrated the precision of the measurement, but isn't the real question the accuracy? There must be many assumptions in creating the mathematical model which does the calculations. This is a difference of only 0.1% to a model position of sea level. Has the model been thoroughly validated? Is the result accurate?

Correct. Only the NGS will validate/invalidate/further investigate.

Know that this network is trusted and tested for survey-grade accuracy and is used heavily for things like heavy-highway engineering. I have used these types of devices for such purposes. I spoke with a representative who said that accuracy should be about 0.2 feet (less than 3 inches) in this area. The network uses known and established surface base stations to create a local VRS...so it's not generated out of thin air, but from near by base stations. I recorded these measurements with the intent to present them to the NGS as so that they will accept/verify. I put my confidence in the results at >99% that the summit is over 4000'.

http://www.keynetgps.com/ is the website.

 

[TJsName]

You have demonstrated the precision of the measurement, but isn't the real question the accuracy? There must be many assumptions in creating the mathematical model which does the calculations. This is a difference of only 0.1% to a model position of sea level. Has the model been thoroughly validated? Is the result accurate?

Ahh, high school chemistry all over again.

 

[dom15931]

RESULTS OF RAPID STATIC ON SUMMIT SIGN. This is an independent check through the NGS's OPUS site. Same Result. It will be exciting to see what they say! ORTHO HGT: 1220.526(m) 0.053(m) [NAVD88 (Computed using GEOID12B)] ... is the important line.


FILE: MACNAUGTON_MTN_SUMMIT_SIGN.tps OP1465158245506

NGS OPUS-RS SOLUTION REPORT
========================

All computed coordinate accuracies are listed as 1-sigma RMS values.
For additional information: http://www.ngs.noaa.gov/OPUS/about.jsp#accuracy

USER: [email protected] DATE: June 05, 2016
RINEX FILE: macn150v.16o TIME: 20:32:53 UTC


SOFTWARE: rsgps 1.37 RS93.prl 1.99.3 START: 2016/05/29 21:28:07
EPHEMERIS: igr18990.eph [rapid] STOP: 2016/05/29 21:56:05
NAV FILE: brdc1500.16n OBS USED: 3312 / 3416 : 97%
ANT NAME: TPSHIPER_PLUS NONE QUALITY IND. 5.05/ 17.79
ARP HEIGHT: 3.108 NORMALIZED RMS: 0.448


REF FRAME: NAD_83(2011)(EPOCH:2010.0000) IGS08 (EPOCH:2016.40957)

X: 1258736.484(m) 0.012(m) 1258735.602(m) 0.012(m)
Y: -4409288.488(m) 0.036(m) -4409287.094(m) 0.036(m)
Z: 4420175.371(m) 0.040(m) 4420175.361(m) 0.040(m)

LAT: 44 8 27.45594 0.016(m) 44 8 27.49141 0.016(m)
E LON: 285 55 57.56850 0.011(m) 285 55 57.54756 0.011(m)
W LON: 74 4 2.43150 0.011(m) 74 4 2.45244 0.011(m)
EL HGT: 1192.433(m) 0.052(m) 1191.290(m) 0.052(m)
ORTHO HGT: 1220.526(m) 0.053(m) [NAVD88 (Computed using GEOID12B)]

UTM COORDINATES STATE PLANE COORDINATES
UTM (Zone 18) SPC (3101 NY E)
Northing (Y) [meters] 4887952.004 589515.348
Easting (X) [meters] 574597.863 184616.129
Convergence [degrees] 0.64955707 0.30131720
Point Scale 0.99966844 0.99991473
Combined Factor 0.99948156 0.99972780

US NATIONAL GRID DESIGNATOR: 18TWP7459787952(NAD 83)


BASE STATIONS USED
PID DESIGNATION LATITUDE LONGITUDE DISTANCE(m)
DI0598 NYLV LOWVILLE CORS ARP N434747.243 W0752907.554 120078.2
DI0610 NYPB PLATTSBURG CORS ARP N444050.582 W0732714.305 77372.7
DI0602 NYML MALONE CORS ARP N445215.384 W0741717.343 83010.0
DI0612 NYPD POTSDAM CORS ARP N443909.059 W0750230.504 96235.0
DK4109 VTRU RUTLAND CORS ARP N433625.639 W0725845.903 105675.4
DJ8959 VTSA ST ALBANS CORS ARP N444832.646 W0730457.288 107951.8
DK7177 NYHL HAILESBORO CORS ARP N441831.547 W0752657.689 112003.6
DI0622 NYST SARATOGA CORS ARP N430341.735 W0734815.010 121805.6

NEAREST NGS PUBLISHED CONTROL POINT
PH0295 M 238 N440739.62 W0740450.88 1827.5