Writing, developed first by people in Sumer, is considered a hallmark of civilization and appears to accompany the rise of complex administrative bureaucracies or the conquest state. Traders and bureaucrats relied on writing to keep accurate records.
Elevation, or geometric height, is mainly used when referring to points on the Earth 's surface, while altitude or geopotential height is used for points above the surface, such as an aircraft in flight or a spacecraft in orbit, and depth is used for points below the surface. topographical map is the main type of map used to depict elevation, often through use of contour lines. In a Geographic Information System (GIS), digital elevation models (DEM) are commonly used to represent the surface (topography) of a place, through a raster (grid) dataset of elevations.
Azimuth and elevation refer to the satellite TV dish pointing angles. Elevation Elevation refers to the angle between the beam pointing direction, directly towards the satellite, and the local horizontal plane. It is the up-down angle. When your dish is pointed low down near the horizon the elevation angle is only a few degrees. At low elevation angles, below 5 deg at C band and 10 deg at Ku band, the path through the atmosphere is longer and the signals are degraded by rain attenuation and rain thermal noise.