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AMSL
Height above mean sea level is a measure of a location's vertical distance (height, elevation or altitude) in reference to a vertical datum based on a historic mean sea level. In geodesy, it is formalized as orthometric height. The zero level varies in different countries due to different reference points and historic measurement periods. Climate change and other forces can cause sea levels and elevations to vary over time. Uses Elevation or altitude above sea level is a standard measurement for: * Geographic locations such as towns, mountains and other landmarks. * The top of buildings and other structures. * Mining infrastructure, particularly underground. * Flying objects such as airplanes or helicopters below a Transition Altitude defined by local regulations. Units and abbreviations Elevation or altitude is generally expressed as "metres above mean sea level" in the metric system, or " feet above mean sea level" in United States customary and imperial units. Comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertical Position
Vertical position or vertical location is a position (mathematics), position along a vertical direction (the plumb line direction) above or below a given vertical datum (a reference level surface, such as mean sea level). Vertical distance or vertical separation is the distance between two vertical positions. Many vertical coordinates exist for expressing vertical position: depth, height, altitude, elevation, etc. Points lying on an equigeopotential surface are said to be on the same vertical level, as in a water level (device), water level. A function (mathematics), function with domain (mathematics), domain along the vertical line is called a ''vertical distribution'' or ''vertical profile''. Definitions The International Organization for Standardization (ISO), more specifically Spatial reference system, ISO 19111, offers the following two definitions: * ''depth'': "distance of a point from a chosen reference surface measured downward along a line perpendicular to that surface." ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |