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good afternoon ,
i live on a hill side overlooking the ocean. i need to know how far above the ocean i am . i have a good angle measuring equipment so i can determine the angle from where im standing to the waters edge inside of a degree i figure but no way to measure the distances to do any basic trig. is there a trick way to do this ?
steven
- 9 Replies
Neglecting refraction, you can solve the right triangle as shown in these links
http://www.ringbell.co.uk/info/hdist.htm
https://en.wikibooks.org/wiki/Trigonometry/The_distance_and_dip_of_the_horizon
https://aty.sdsu.edu/explain/atmos_refr/dip.html
.
You could throw a baseball from your yard and time the interval until you see the splash. Factor in parabolic motion of the baseball’s flight, the rate of acceleration due to gravity, your arm speed, wind resistance, tidal state and the height of ball release above ground, then you can approximate the difference in elevation.
Easy peasy …
google earth?
@stevesxm
Quad Map?
Just wondering….
Is this in any manner related to the question of elevation, for purposes of flood statement?
Or flood insurance?
N
@stevesxm
Go to the National Map Viewer:- Navigate to where you want to be on the map using pan and zoom
- Pick the tool that says xy (spot elevation)
- Pick the point on the map that you want to know the elevation (anywhere in the USA)
- Simple subtraction to see the difference in elevation between points.
Easy Peasy…
I’ve found this method to be very accurate; your mileage may vary
I hope everyone has a great day; I know I will!
is there a trick way to do this ?
1. Easiest and most accurate way is to call a surveyor, who will come out with some equipment and give you an answer pretty quick.
2. If not that, well, you are going to need to get a distance measurement somewhere in the equation. One way would be to slope tape, if the distance is not too great. Another would be to pick up one of those electronic distance measuring things from Home Depot. The best one they have has a range of 825 ft, and will measure the vertical angle and convert to vertical distance. Possibly such a device could be rented by the day?
3. Another way would be to have someone hold a 10 foot 2×4 up (vertically) at the waters edge and measure the vertical angle from the top of the bank to both the top and bottom of the board, and solve the remainder of the non-right triangle elements by the cosine rule. Theoretically possible, but the sources of error will add up to be pretty great.
4. Use the altimeter built into your smartphone. Various apps can be had for free. Probably give a result +/- 10 feet.
5. Various schemes to do some levelling down the slope, using a true surveyors level and rod you might rent, a hand level (aka/ pea shooter) or even just a carpenters level and a marked up 2×4 as a level rod.
Agreed – for horizontal distance of site to shoreline.
In the old days to measure across a body of water for example, surveyor would establish a baseline of a known length parallel to waterbody and turn horizontal angles to a flag set on the far bank from both end of the baseline and solve the distance using basic trig. Once you know the horizontal distance from where you are to shore, measure the zenith or vertical angle to create another right angle triangle to solve for the height above the shore. Get you close anyway.
Willy
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