Search results
Results from the WOW.Com Content Network
Datum surface – reference plane with respect to which RL of the other survey points is determined. The datum surface may be real or imaginary location with a nominated elevation of zero. The commonly used datum is mean sea level. [3] Dumpy level – optical instrument used to establish or check points in the same horizontal plane. It is used ...
In topography, a nadir is a point on a surface that is lower in elevation than all points immediately adjacent to it. [1] Mathematically , a nadir is a local minimum of elevation. A nadir may be the lowest point of a dry basin or depression , or the deepest point of a body of water or ice .
Turning is a term used when referring to moving the level to take an elevation shot from a different location. To "turn" the level, one must first take a reading and record the elevation of the point the rod is located on. While the rod is being kept in exactly the same location, the level is moved to a new location where the rod is still visible.
Height above mean sea level (AMSL) is the elevation (on the ground) or altitude (in the air) of an object, relative to a reference datum for mean sea level (MSL). It is also used in aviation, where some heights are recorded and reported with respect to mean sea level (contrast with flight level ), and in the atmospheric sciences , and in land ...
This is a list of places on land below mean sea level. Places artificially created such as tunnels, mines, basements, and dug holes, or places under water, or existing temporarily as a result of ebbing of sea tide etc., are not included. Places where seawater and rainwater is pumped away are included.
Terrain (from Latin: terra 'earth'), alternatively relief or topographical relief, is the dimension and shape of a given surface of land. In physical geography, terrain is the lay of the land. This is usually expressed in terms of the elevation, slope, and orientation of terrain features. Terrain affects surface water flow and distribution.
Level (optical instrument), a device used to measure true horizontal or relative heights; Spirit level or bubble level, an instrument designed to indicate whether a surface is horizontal or vertical; Canal pound or level; Regrading or levelling, the process of raising and/or lowering the levels of land; Storey or level, a vertical unit of a ...
Hypsometry (from Ancient Greek ὕψος (húpsos) 'height' and μέτρον (métron) 'measure') [1] [2] is the measurement of the elevation and depth of features of Earth's surface relative to mean sea level. [3] On Earth, the elevations can take on either positive or negative (below sea level) values.