ENTS
I looked at the specifications of OPTILOGIC hypsometers in models 100LH, 400LH, 800LH, 1000LH. The height routine described in the directions is the 3 measurement, tangent-based routine. That won't work for ENTS for the reasons that we frequently discuss on the list. Too bad. However, their hypsometers do return vertical angle. So, it could be used with target distance like a clinometer-rangefinder combination, but that requires the operator to do the math. Maybe there is another OPTILOGIC instrument that uses the sine-based procedure. I found the user manual PDF file to be very good. Bob ----- Original Message ----- From: "MyCamel" <[email protected]> To: "ENTSTrees" <[email protected]> Sent: Sunday, January 3, 2010 10:55:41 PM GMT -05:00 US/Canada Eastern Subject: [ENTS] Re: Suunto vs. iPhone Opti-Logic manufactures several Hypsometers http://www.opti-logic.com/lh_series.htm they have 2 and 3 point height measurements. On Jan 3, 2:35 pm, Carolyn Summers <[email protected]> wrote: > 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 <[email protected]> > > Reply-To: <[email protected]> > > Date: Tue, 22 Dec 2009 15:57:09 -0800 (PST) > > To: ENTSTrees <[email protected]> > > 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 the left side. I think someone > > thought of this earlier. With the sight and practice I believe one > > could the angle down to the nearest tenth of a degree. With the > > Suunto one can only really estimate anything less than 1 degree. > > Beth > > > -- > > Eastern Native Tree Societyhttp://www.nativetreesociety.org > > Send email to [email protected] > > Visit this group athttp://groups.google.com/group/entstrees?hl=en > > To unsubscribe send email to [email protected] Hide > > quoted text - > > - Show quoted text - -- Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected] -- Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected]
