John, Andrew, Will, ENTS,
In the the last email, I left out what the average is when I take all the
measurements at face value. The original measurements are.
51.50 41.60 102.58 40.00 24.60 49.95 4.50 157.03 Thoreau
54.50 34.10 91.66 47.50 25.30 60.90 4.50 157.06 Thoreau
51.50 41.70 102.78 40.00 24.60 49.95 4.50 157.23 Thoreau
54.50 34.20 91.90 47.50 25.30 60.90 4.50 157.30 Thoreau
57.50 29.00 83.63 54.00 25.60 70.00 4.50 158.13 Thoreau
60.00 29.20 87.81 53.50 24.00 65.28 4.50 157.60 Thoreau
61.50 27.80 86.05 59.00 22.40 67.45 4.50 158.00 Thoreau
73.00 17.20 64.76 76.00 22.90 88.72 4.50 157.98 Thoreau
0.00 0.00 0.00 157.54
The average of the two sets of measurements is 156.8 feet. I could see that as
a fairly defensible determination. I don't think any of my distances are short,
just some of them long - but not all. Regardless, we're going to be under 158
feet. Until the tree is climbed again and a second tape drop measurement
established, I'm going to record Thoreau as 156.8 feet - unless you all argue
me out of it. I'll go with the consensus.
Bob
----- Original Message -----
From: [email protected]
To: [email protected]
Sent: Sunday, December 6, 2009 8:34:33 AM GMT -05:00 US/Canada Eastern
Subject: [ENTS] Settling the issue on Thoreau
John, Andrew, Will, ENTS,
What follows is something for us to really think about. To distant targets, my
Nikon 440 often shoots long by 0.5 yards. I'd say this happens about half the
time. When repeatedly shooting a target, I will usually get two populations of
bounces that differ by 0.5 yards. I can choose the higher, the lower, or
average the two. However, I often give the tree the benefit of it doubt,
especially when shooting a tree for the first time. The following table shows
conservative measurements where I've taken off 0.5 yards from each distance
measurement to the top and the base. Almost all original distances were the
longer of the two populations and all were taken while Andrew and team were
still climbing. I've left the angle measurements alone. They are from my very
accurate TruPulse 360.
CD = crown distance
CA = crown angle
HA = height above eye level
BD = base distance (to John's tag)
BA = base angle
HB = height below eye level
OFF = height of John's tag
TH = total height
CD CA HA BD BA HB OFF TH
51.00 41.60 101.58 39.50 24.60 49.33 4.50 155.41
54.00 34.10 90.82 47.00 25.30 60.26 4.50 155.58
51.00 41.70 101.78 39.50 24.60 49.33 4.50 155.61
54.00 34.20 91.06 47.00 25.30 60.26 4.50 155.81
57.00 29.00 82.90 53.50 25.60 69.35 4.50 156.75
59.50 29.20 87.08 53.00 24.00 64.67 4.50 156.25
61.00 27.80 85.35 58.50 22.40 66.88 4.50 156.73
72.50 17.20 64.32 75.50 22.90 88.14 4.50 156.95
0.00 0.00 0.00 156.14
The tape dop height was 156.1 feet. The average of the distance adjusted
measurements I took is 156.14. Using a similar method of averaging is how I
came to within 0.1 feet of the tape drop measurements for both the Jake Swamp
and Joe Norton trees. I have always recognized the need to take multiple
measurements, search for patterns, eliminate improbable measurements and
average the rest. I'm sure that I wanted to believe the Thoreau pine is not
less than 158 feet. I hoped for 160, but hav enever gotten that. So, in this
case, I didn't do my usual averaging, especially since John was getting similar
measurements to mine at the time we were comparing them.
My adjustments suggest that the top we measured is truly 156.1 feet above
mid-slope. We'll have to accept that Thoreau's 13.0-ft girth as making up the
difference. If we take a 13-ft girth, the 156.1-ft height, a form factor of
0.4, we get 839.7 cubic feet of trunk volume. It was measured at modeled to
around 816 cubes in 2004. So, 840 cubes now sound pretty close. Do I hear any
other volume bids? Going once, going twice - SOLD!
Bob
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