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You could look at the manual, if there is one. Or, from a known distance, measure the angle from horizontal to the top. A little very simple math completes the trick:
So we need to measure angle e. How to do?To measure the heights and distances of different objects, we use trigonometric ratios.
Use the Tangent rule to calculate the height of the tree (above eye level).
tan(angle) = opposite/adjacent
Where the opposite is the height of the tree and adjacent is the distance between you and the tree.
This is rearranged to:
opposite = tan(angle) x adjacent
or more simply
height=tan(angle)×distance
Distance can be calculated as:
B (distance)=A (height)tan (e)
Therefore, to calculate B
(distance) we will need the value of A (height) and angle e.
You could do it with trying to sight along a protractor, like you used in school for measuring angles, or like the sailor, use a sextant.
Sextants are usually expensive instruments, accurate for navigation, but a simple wood one is good enough for antennas and towers.
This one is $10.75 from Amazon, ASIN B0CN6JDD26 . At this price, know that some simple assembly is required:
All the same, good enough to measure the height angle. Hint with this simple wood device: first sight a zero angle and see what the sextant scale reads. Use this "zero" reading with the angle sight to give a true angle. -Or spend over a Grand on a real sextant!
So now I know how high is my antenna, the house, and some potentially useful high pine trees. Very cool!
Thank you https://www.cuemath.com for the nice pictures.