# How does surveying work?

Asked by andrew (16553) April 15th, 2008

I’ve looked at the wiki articles on surveying and theodolite, but especially after seeing There Will Be Blood I’m curious as to how sighting a target from a tripod actually measures distance. Does it have to do with the curvature of the earth?

Observing members: 0 Composing members: 0

I suspect it has more to do with trigonometry and triangulation, but I’m not a surveyor.

cwilbur (14236)

Okay, that’s a REALLY creepy coincidence… The architecture students were all standing in the grass when I walked in the building. They were doing their official Surveying class (day).

(They were also incredibly rude because none of them held the door for the little art student carrying two massive 20” sketch pads, her laptop, her purse, a sculpture that was due, her acrylics toolbox, her massive paint bag with her watercolors and extra stuff she might need to draw with. So she (me) had to stand outside the door until some nice stranger came and helped. )

So, i’d go and ask them if they weren’t a bunch of jerks.

delirium (13718)

You must have two fixes on the target, from two different base locations. You measure the angle from N to the target at both locations, measure the distance between the two locations, and then you have enough data to construct a triangle. You can solve the triangle to find the distance from either base location to the target. This also works for height of target, if you take the right measurements.

steelmarket (3603)

@delirium, don’t take it personally. Architect-types tend to get target fixation, so they were probably not dissing you, they just did not see you.

steelmarket (3603)

Hahaha, thanks steel, sadly they were less than a foot away and talking amongst themselves about me loudly enough that I could hear it.

delirium (13718)

In that case, they were just your average jerks. My apologies for all those of my profession.

steelmarket (3603)

Apology accepted. At least some of you architects are gentlemen. ;)

delirium (13718)
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