Bob, Thank you. When it comes to mathematics concerning tree spread or anything else, you are the one to ask. Your knowledge of equipment is exceptional too.
James P. On Jan 6, 9:12 am, [email protected] wrote: > 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 > > ... > > read more »- Hide quoted text - > > - Show quoted text -
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