Saturday, October 13, 2018

Elevation Measurement for Dummies

geometry compass
Geometry compass
You'd like to think that a freelancer writer (even one who's self-appointed) would know the meaning of circularity, not to mention have the chops necessary to reword a reference that's at about the fifth-grade reading level. You would like to think that, wouldn't you... Such is not always the case, however, with the freelancers who plied their trade (such as it is) for eHow.com, freelancers like John McDaniel (originally writing under the name Byrd McDaniel) and his article "How to Measure Elevation" at Sciencing.com.

McDaniel opened with the monumentally uninformative statement,
"Measuring elevation requires a series of complicated measurements."
Sounds like someone didn't take any science courses on the way to that BA in Chinese literature! And that assessment is borne out by the rest of Byrd's post, in doofus statements like,
"Most scientists today measure the elevation of mountains by placing radios on the peaks of a mountain range, after which, satellites take measurements and determine the elevation."
Sure, but what does that "satellite" measure, anyway? Could it be, oh, we dunno, travel time for radio signals? And then there's,
"Use a geometry compass to determine the angle from the ground to the top of the object, your point of interest."
WTF is a "geometry compass," anyway? Does McDaniel mean a protractor? a clinometer? a transit? Byrd finishes up by telling his readers to,
     
"Plug your numbers into the equation: tangent x = b/a... Solve the equation for "b", by multiplying "a" by the tangent of your angle."
Ummm, we're pretty sure that's not a particularly accurate method of determining the elevation of a mountain peak, which is what McDaniel thinks we're doing: a slight error in measuring the angle could have a heckuva big influence on the result... Oh, and Byrd? John? Whoever? that's not exactly what we'd call "taking precise measurements of slopes and angles."
No, McDaniel was on the right track with the radio altimeter stuff (he could also have mentioned barometric altimeters). Where he went wonky, however was his bullcrap about a "geometry compass"; which he compounded by instructing readers to "point the needle" at some point. Geometry compasses have needles?

What a moron... but what a fine Dumbass of the Day McDaniel makes!
copyright © 2018-2022 scmrak

SI - SURVEYING

No comments: