estimating height of trees

[ssurveyor]

trimble total station

You could go the high tech way. The reflectorless laser shows the height with a point and shoot function.

 

[imagineero]

I've got the bosch laser rangefinder, and from memory its accurate to about 1/8" over 150'. I use it mainly for carpentry work and estimating when I do house painting. It doesnt have a clinometer, but it can work out square metreage of squares, rectangles and triangles as well as cubic metres. It orks great in the dark, or inside houses, but I find it near useless for measuring trees since the dot is small and not very bright in direct sun.

The ruler scale method is useful for me partly because of working out if I have space to drop, but mainly because a big part of my quoting has nothing to do with dropping trees. I can take a look at most trees and pretty quiclly guess how long they'll take to climb ad bring down, but I find it a lot harder to estimate dumping and 'moving' costs.

I don't have a chipper, or a truck, so I end up taking wood to the tip in a trailer. Since I live in the mountains, there's rarely good access. Most trees are on a slope, can't get anything into the yard etc, so everything has to be carried by hand. With the height of the tree and a log chart I can estimate tonnage, which gives me my dumping fees, and then I keep track of tonnage, slope and distance carried to get some kind of idea how many man hours I need to get it to the trailer. Maybe in a couple of years I'll be able to eyeball all this accurately, but with so many variables (species, height, diameter, spread) I think I'll stick with the ruler and chart.

It sounds complicated, but it really isn't. Works really great in a yard with multiple trees, and our trees hear usually have very bad form with no single dominant leader. bifurcated and trifurcated trunks are common, and heavy heavy branches. with a chart at my side and a bit of paper, 2 or 3 minutes is enough time for me to go "20' of trunk at 3', 20' of trunk at 2'" etc... then I just measure the length of all the branches the same diameter like "ok, 8" branches... 10', 15', 8', 10'" add them all up and add a bit for canopy and you've got a pretty accurate tonnage right there. This really reduces the 'fudge factor' when you've got quite a few trees in a yard to remove.

Shaun

 

[treeslayer]

I wish we could pair up in KC. I'm not really too hot up in a tree, but I am pretty masterful at felling them.

Kansas city ain't that far from me, got work?

 

[Nailsbeats]

I run a 45 degree angle with my arm then back up until it touches the top of the tree, drop back another six feet and it won't go past there. Cut high on the stump if you want to shorten it up, as has been mentioned, and depending on the notch and how you backcut it, you should know whether you are going to jump it off the stump or keep it hooked up and figure that into the distance too.

 

[moss]

If you're interested in very accurate measurement...

However, my Nikon warns that it is accurate from 1 to 3 yards +-. That is roughly 3 to 9 feet. Not enough to worry about for archery but that is quite a margin of error for dropping a tree. Be careful if you use the rangefinder...

Ok I'll bite. I measure trees for documenting heights of notable trees. I use a Nikon 440 Rangefinder and a Suunto manual clinometer. That particular rangefinder has 1.5' margin of error. To correct you just back up while you're sighting a top twig until the distance reading clicks over say from 60 yards to 60.5 yards, that removes the error. Then get the angle to the top with a clinometer. Take a calculator and do a sine function on the angle to the top then multiply by the distance to the top twig (60.5 yards) x 3 to convert to feet and you have the height of the tree from your eye level to the the top. Repeat the same for the distance and angle to the bottom, add the two values and you have total height. Sounds complicated but you can do it in about a minute standing in one place.

It's called the "sine top/sine bottom" method. Eastern Native Tree Society has a detailed writeup on it on their web site.

I've participated in a number of measuring tests where I climb and do a manual tape drop measurement from the top of the tree and compare to other folks measuring from the ground, typical error between the tape and sine top/sine bottom technique is in the 1-3" range on 150 to +160' trees.

Stick trick or clinometer only measurement tends to overestimate, sometimes by 15' or more. Not a problem for felling but not good for measuring champion trees for example or when you want a very accurate measurement.
-AJ

 

[pdqdl]

Kansas city ain't that far from me, got work?

No. Right now it is dreadful. I wish I could keep you busy, but heck. I can't keep myself busy right now. Everybody seems to be saving money for Christmas.

Today, we got our first call this week for any sort of treework. We are trimming the police station tomorrow.

 

[tree md]

Ok I'll bite. I measure trees for documenting heights of notable trees. I use a Nikon 440 Rangefinder and a Suunto manual clinometer. That particular rangefinder has 1.5' margin of error. To correct you just back up while you're sighting a top twig until the distance reading clicks over say from 60 yards to 60.5 yards, that removes the error. Then get the angle to the top with a clinometer. Take a calculator and do a sine function on the angle to the top then multiply by the distance to the top twig (60.5 yards) x 3 to convert to feet and you have the height of the tree from your eye level to the the top. Repeat the same for the distance and angle to the bottom, add the two values and you have total height. Sounds complicated but you can do it in about a minute standing in one place.

It's called the "sine top/sine bottom" method. Eastern Native Tree Society has a detailed writeup on it on their web site.

I've participated in a number of measuring tests where I climb and do a manual tape drop measurement from the top of the tree and compare to other folks measuring from the ground, typical error between the tape and sine top/sine bottom technique is in the 1-3" range on 150 to +160' trees.

Stick trick or clinometer only measurement tends to overestimate, sometimes by 15' or more. Not a problem for felling but not good for measuring champion trees for example or when you want a very accurate measurement.
-AJ

I stand corrected Moss.

I still had the box and paperwork on mine. Sure enough, it says accurate to 1/2 yard. I must have been thinking of the older models.

Good info on estimating. Like you said, the most accurate way to measure is to climb them and drop tape. Love the Explorer episode where they are climbing the Redwoods in California.

 

[moss]

I stand corrected Moss.

I still had the box and paperwork on mine. Sure enough, it says accurate to 1/2 yard. I must have been thinking of the older models.

Good info on estimating. Like you said, the most accurate way to measure is to climb them and drop tape. Love the Explorer episode where they are climbing the Redwoods in California.

Plus hanging a tape is a great reason to climb awesome trees.

Not trying to one up you on the rangefinder spec. Try moving closer or back while holding down the power/scan button (clickover technique), you'll negate the 1/2 yard range of error when the distance value changes up or down .5 yard.

There's a big silver maple in a well known arboretum near where I live. They put a sign in front of it saying it's 126', which would make it the tallest of the species in Massachusetts I believe. Best I could get with rangefinder and clinometer was 108'. Tough one to measure because of wide crown at the top and typical silver maple multiple leaders. A friend who's been honing his measuring skill for many years got 113', the most height that can be milked out of that one. We've contacted the arboretum and explained the technique and results. They took the 126' sign down but haven't responded to us People hate it when you tell them their tree is shorter than they thought, understandable.
-AJ

 

[moss]

I've seen the rangefinder your talking about advertised but I haven't had the chance to get one in my hot little hands and play with it. Supposed to be super accurate from what I have read. It is advertised to compensate for angles from the heights of tree stands and give you a true range. I would love to play with one and compare it to my older Nikon 440. The 440 is fine for estimating range for archery. 10' is not really going to matter in most cases within 40 yards.

Funny thing happened, the Nikon engineers screwed up on the Forestry 550, it doesn't pick through all the small branches to reach the target top twig as well as the 440. The 440 is uncannily good in that regard even better then super fancy multifunction forestry rangefinders that cost well over $1000 bucks. So I'd treasure that inexpensive little piece of gear.
-AJ

 

[tree md]

Funny thing happened, the Nikon engineers screwed up on the Forestry 550, it doesn't pick through all the small branches to reach the target top twig as well as the 440. The 440 is uncannily good in that regard even better then super fancy multifunction forestry rangefinders that cost well over $1000 bucks. So I'd treasure that inexpensive little piece of gear.
-AJ

I can even get accurate readings shooting it through a mesh window. I was amazed. It is pretty nice. 5 years and I am still using the same lithium ion battery.

 

[sgreanbeans]

Though I don't measure height, if it something to be talked about, then it doesn't get felled. what about shooting the throw bag up top, marking the line every 10', tie a biner in at the bottom (too mark the bottom), pull it out, measure 10' increments?
Just a thought