James,
I'll get to your questions today. There's a lot to talk about.
Bob
----- Original Message -----
From: "James Parton" <[email protected]>
To: "ENTSTrees" <[email protected]>
Sent: Tuesday, January 5, 2010 10:31:19 PM GMT -05:00 US/Canada Eastern
Subject: [ENTS] Re: Laser History and Measuring Tree Spread.
Bob, Also have you tried out one of those electronic clinometers like Haglof
makes? Come to think of it, I think Larry Tucei has one of those. I just wonder
how they compare with the Suunto. JP On Jan 5, 11:38 am, James Parton wrote: >
Bob, > > Thanks for the explanation. One thing is for sure, I enjoy measuring >
trees by this method when I am out. I think I have it pretty much down > but
still I need more practice at being proficient at it. I was going > over what I
learned at Congaree last year, doing tree spread. They are > a couple of ways.
Take two measurements, four spokes and average them. > Say 15y by 20y. You
would add them together and divide them by two to > get the average. right? And
then take the answer and times that by > three to get it in feet. 15+20=35
divided by 2=17.5 x3 = 52.5 That is > 52.5 ft average spread. I also seen in
Congaree where multiple > measurements are made by circling the tree making
multiple > measurements for improved accuracy. I looked up and read on how to >
measure max and average spread on the website but wanted to know > whether I
had the averaging number formula right. I never was a math > wiz. ~laughing~! >
> I find it awesome that ENTS and a few independents have influenced > tree
measuring so much that Nikon and others now produce rangefinders > to cater to
that need. As you stated, before us rangefinders were made > primarily for
sporting activities. Hunters still use them a lot, for > example. > > I have to
thank all ENTS but especially You, Larry Tucei, Will Blozan > and Ed Frank for
helping me learn this amazing method. I would > encourage all non measuring
ents to learn it. It really is fun! > > James Parton > > On Jan 5, 9:39 am,
[email protected] wrote: > > > > > James, > > > BVP was independently using
the sine top sine bottom method first. There may have been others as well, but
I'm unaware of who they would have been. Will Blozan and I developed sine top
and sine bottom for ENTS. We later discovered that BVP and been using it for a
long time. Colby Rucker later joined Will and me and became known for his use
of long poles to get a better fix on the lower measurement. Colby was just
great. I miss him a lot. We all do. > > > BVP was the one who introduced Will
and me to the Litespeed 400, a Bushnell laser. I got one and so did Will.
Everything was uphill thereafter. The rest is history. > > > In terms of the
tree math, my strong suit has always been mathematics. I developed mathematical
models in my work while in the Pentagon and have taught math and statistics at
the college level. So, tackling the problem in a mathematical way conforms to
my nature. I say this because it has always come as a surprise to people
outside the world of forestry that such basic calculations as we use haven't
been in practice for decades. I always explain that those calculations were not
possible prior to the introduction of the laser rangefinder. As to the
expertise of mensurationists, they know the math. It's elementary, but they
don't spend the time decoding hard to measure trees in forest situations. It's
rather like knowing some principles of animal tracking versus being out there
doing it. It took me three separate trips to tie down that tuliptree in
Montpelier. I'm within +/- 0.5 feet of the twig I was measuring, but the effort
required speaks to the difference of pointing, shooting, and writing down some
numbers versus getting it right. ENTS knows better how to do that than any
other group in the East. Of that, I have no doubt. > > > The Forestry 550 does
measure tree height by our sine top, sine bottom method. The TruPulse does it
also, but not by the built in height routine. It requires mores steps. BVP's
Impulse Laser also does it right, but not by the built in routine. He also must
use more steps. The OPTILOGIC appears to do it by the old tangent method. Pity.
> > > Before ENTS people were using laser rangefinders in sports and other
endeavors, but judging by the feedback we have gotten, ENTS has been really the
only show in town in terms of employing laser rangefinders in tree height
measuring. There's no way of knowing who might have been out there in tree-land
doing it on their own. They didn't come forward. > > > The tangent-clinometer
method was used before ENTS. It has been in use for decades. I suspect that
early measurements of standing trees employed this method with some instrument
being used to measure the vertical angle. The method of similar triangles would
also have been used. Descriptions of equipment used and measuring methodology
have been lost, if they were ever known. Thus, we get reports of astounding
tree heights, but no way of verifying them. We'll never know what grew in
centuries past. > > > A laser by its self can be used as you describe. However,
looking upward and trying to shoot exactly straight up (90 degrees) is harder
than one might imagine. When you think you are looking straight up, it is often
at an angle of 70 to 75 degrees. A short make shift plumb bob can be used to
create a true vertical line. > > > I think this covers everything. > > > Bob >
> > ----- Original Message ----- > > From: "James Parton" > > To: "ENTSTrees" >
> Sent: Monday, January 4, 2010 10:47:21 PM GMT -05:00 US/Canada Eastern > >
Subject: [ENTS] Re: Suunto vs. iPhone > > > Bob, > > > ENTS came up with the
Sine-Top Sine-Bottom method of measuring, right? > > I also know that some
others have used lasers to measure trees more > > recently? Has ENTS inspired
the use of laser rangefinders as tree > > measuring tools so much to grab
Nikon's attention to build a laser > > specifically for measuring trees? And
then there is those Tru-Pulse > > lasers and the one that BVP uses. Was lasers
being used of any > > frequency before ENTS? I have always thought the tangent
clinometer- > > only method was in use before You and Will developed our highly
> > accurate method. I also know that a laser can be used by itself from > >
under the tree if the top can be found as in a decideous tree in > > winter
without the need of the clinometer. > > > Fill me in on laser usage history. >
> > James Parton > > > On Jan 3, 3:19 pm, [email protected] wrote: > > >
Carolyn, > > > > The Nikon Forestry 550 does it all. It is also fairly pricey.
You select the height mode, shoot the crown, shoot the base, and read the
calculated height from the LED. No math. No fuss. No bother. > > > > Bob > > >
> ----- Original Message ----- > > > From: "Carolyn Summers" > > > To:
[email protected] > > > Sent: Sunday, January 3, 2010 2:35:23 PM GMT
-05:00 US/Canada Eastern > > > Subject: Re: [ENTS] Suunto vs. iPhone > > > >
Are there any tree-height measuring devices that do the math for you? I > > >
never took trig. > > > -- > > > Carolyn Summers > > > 63 Ferndale Drive > > >
Hastings-on-Hudson, NY 10706 > > > 914-478-5712 > > > > > From: Beth > > > >
Reply-To: > > > > Date: Tue, 22 Dec 2009 15:57:09 -0800 (PST) > > > > To:
ENTSTrees > > > > Subject: [ENTS] Suunto vs. iPhone > > > > > A Small
Comparison between Suunto and iPhone Clinometers > > > > > Since some of us now
have iPhones and have downloaded the > > > > Clinometer application I thought
that someone needs to compare the > > > > iPhone to the Suunto clinometer.
Today I took 14 measurements each > > > > while sitting on my couch to a
ceiling heating/AC vent. I then > > > > measured my eye height, the ceiling
height, and the distance from my > > > > eyes to the tape measure hanging from
the vent as a plumb bob. These > > > > measurements were: ceiling height = 96²,
height of the eyes = 38², and > > > > distance to the vent plum bob = 219². I
used the measurements to > > > > calculate the angle I was trying to measure
with the Suunto and > > > > iPhone. Before taking my measurements I calibrated
my iPhone > > > > clinometer according to the instructions. I also had the
following > > > > settings: Fast approximation-on, Beep on lock-on, wait for
lock > > > > accuracy of + 0.1o- all the way to the left (+ 0.1o), disable
auto- > > > > lock-off, and 3D glass effect-on. > > > > > The first thing that
I do in order to calculate the angle A was to > > > > calculate the distance
from my eye to the ceiling; 96²-38²= 58². > > > > > Since Tan A = a/b, we can
rearrange the equation to find A by dividing > > > > both sides by Tan. Since
1/Tan =Arc Tan the equation is A = (a/b) Arc > > > > Tan. Filling in this
equation with the data we get A = (58/219) Arc > > > > Tan or A =
14.8336707057. Taking signifiginte numbers in mind I am > > > > going to say
the angle is 14.8o. (Note: I calculated this after > > > > gathering the data
as not to influence the clinometer data) > > > > > Now for the clinometer data:
> > > > Suunto iPhone Suunto iPhone > > > > 15.5 15.2 14.5 15.4 > > > > 15.0
14.9 15.0 15.2 > > > > 15.0 15.1 14.5 15.2 > > > > 15.0 14.1 14.5 15.1 > > > >
15.0 15.0 14.5 15.7 > > > > 15.0 15.2 15.0 15.5 > > > > 14.5 15.1 14.5 15.2 > >
> > The means were 14.8 and 15.1 for the Suunto and iPhone respectively > > > >
with standard deviation of 0.31 and 0.35. > > > > > The one thing I noticed in
my raw data is with the Suunto my highest > > > > and lowest angles were 15.5
and 14.5 whereas with the iPhone they were > > > > 15.7 and 14.1. I can think
of at least two reasons why. 1) I have > > > > more experience with the Suunto
than I have with the iPhone and 2) the > > > > Suunto has a line to help
repeatly ³hit² the same spot whereas the > > > > iPhone you are just looking
down one side of the phone. > > > > > I also noticed after calculating the
angle (14.8) the Suunto average > > > > was closer than the iPhone¹s (14.8 vs.
15.1). Now is 0.3o difference > > > > significant? Bob has more experience with
the Suunto than I do and he > > > > has stated in the past that can read it to
the nearest 1Ž4 o. I myself > > > > can only read it to the nearest 1Ž2o. Given
this I believe that a > > > > difference of 0.3o is. > > > > > How can the
iPhone be improved? If one would add a sighting device on > > > > to the iPhone
this could help ³hit² the same spot repeatly. Obviously > > > > this can not be
same one that is used in the Suunto¹s, looking through > > > > it with an
optical illusion. Maybe a tiny gun sighting built into the > > > > volume
and/or ringer buttons on > > ... > > read more »- Hide quoted text - > > - Show
quoted text -
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