how a place's height is measured in sea level?

Question

every place has a height above sea level,how it is determined and is there any standard rule.
netherland is below sea level,how it is possible?

Answer 1

Altimeter
Check these links for a more detailed info...
http://bubl.ac.uk/org/tacit/tac/tac43/theuseof.htm
http://imagingeverest.rgs.org/concepts/Virtual_Everest/-288.html
http://en.wikipedia.org/wiki/Surveying
http://hypertextbook.com/facts/2001/BeataUnke.shtml

Do rate if these had helped u understand...

Answer 2

The concept of a "mean sea level" is in itself rather artificial, because it is not possible to determine a figure for mean sea level for the entire planet, and it varies quite a lot even on a much smaller scale. This is because the sea is in constant motion, affected by the high and low pressure zones above it, the tides, local gravitational differences, and so forth. The best one can do is to pick a spot and calculate the mean sea level at that point and use it as a datum. For example, the Ordnance Survey uses a height datum based on the measurements of mean sea level at a particular gauge at Newlyn, Cornwall from 1915 to 1921 for their maps of Great Britain, and this datum is actually some 80cm different from the mean sea level reading obtained on the other side of the country. An alternative is to base height measurements on an ellipsoid of the entire earth, which is what systems such as GPS do. In aviation, the ellipsoid known as World Geodetic System 84 is increasingly used to define mean sea level

Answer 3

The term above mean sea level (AMSL) refers to the elevation (on the ground) or altitude (in the air) of any object, relative to the average sea level. AMSL is used extensively in radio (both in broadcasting and other telecommunications uses) by engineers to determine the coverage area a station will be able to reach. It is also used in aviation, all heights are recorded and reported with respect to AMSL (though also see flight level), and in the atmospheric sciences.

When referring to geographic features such as mountains on a topographic map, variations in elevation are shown by contour lines. The elevation of a mountain denotes the highest point or summit and is typically illustrated as a small circle on a topo map with the AMSL height shown in either meters or feet or both.

The height above average terrain (HAAT) for a station is determined from topographic maps by averaging the elevation AMSL at points along several radials or radii. This is subtracted from the elevation AMSL of the antenna, including both the tower itself and the ground it is on, to determine the difference. Negative numbers for HAAT sometimes result from this when the station or airport is in a valley, which is significantly lower AMSL than the surrounding mountains. In the rare case that a location is below sea level, AMSL itself is a negative number. For one such case see Schiphol Airport.

AMSL is also important to engineers in high-elevation areas because some equipment is not designed with enough airflow for sufficient cooling in the thin air, which can cause overheating, damage, and failure of the electronic components within a transmitter.

Answer 4

Several methods are used. The oldest is triangulation; a line is laid out from a point of known elevation to the point of interest and the changes from level are measured with a transit. Altimeters, which measure atmospheric pressure, can give useful data. Most recently, GPS technology enables measurement of altitude to high precision. Elevations are measured from mean sea level -- the average height of the ocean. Netherlands, much of which is below sea level, stays dry with a system of dikes and pumps.

Answer 5

Consider a ship floating on the sea. The lower levels of the ship are below sea level, but since the lower levels are surrounded on all sides by walls that extend above sea level, the water cannot get in.

It's the same situation with the Netherlands.

Answer 6

All Indian railway track was fixed by MSL+5.2, so you can measure from here!

Answer 7

Go on vikipedia . Type see level and get all details.

Answer 8

its measured by using echo technique where sound is sent thru water and time it reaches back

Answer 9

none hi