How do they measure distance from sea level??????

Question

Ever wonder when you see the Board on which they mention the distance of the place from the sea level do you know how do they do that?????????????????????????????????

Answer 1

First, sea level is basically the average height of the water. It gets a lot more complicated than that but see ref 1 for a good explanation.
How the altitude is determined has changed over the years. It used to be done by a manual system of surveying using instruments such as transits. Today the location and altitude of a spot on earth can easily be determined by satellite using GPS equipment.

Answer 2

JimGeek has the right slant to this question. The oldest way to measure elevation was done by barometric pressure. Since atmosphere pressure was determined and established as a constant, 14.7 psi at sea level, the decrease in pressure as elevation increased is a basic mathematical function.

Answer 3

They install a mirror on a mountain top, then send a laser beam at it from the shore, then determine the distance to the mirror by means of interference measurements, then measure the angle of the beam to horizon, then calculate the altitude by means of trigonometry.

Answer 4

With satellites and tide gauges. Satellites can record the level of oceans around the globe, while tide gauges are used to measure the height of water with respect to a fixed, nearby point on land.

Answer 5

It's not the distance from sea level, it's the elevation of the land above sea level. (or in new orleans' case below sea level)

Answer 6

It is done 2 ways by aircraft, by barostatic altimeters, they have a bellows that reacts to atmospheric pressure and transduce this to altitude and they use radar altimeters, which use radar to reflect off whatever is below, water, or mountains. Radar altimeters warn aircraft of upcoming danger of mountains, barostatic types do not. Modern day aircraft also have laser devices to measure this.

Answer 7

Your question is good yet i think of of no longer on your ingredient.... there's a term referred to as atmospheric rigidity. I skill the rigidity exerted via air. This rigidity is distinctive for particularly some heights. Lesser the top extra suitable is the rigidity. So we calculate top of Mt. Everest using trigonometry *maths phenomena* and the top of its base sort sea ingredient using atmospheric rigidity. If u desire to nicely in many situations going on extra suitable approximately it digital mail me.