Search results
Results from the WOW.Com Content Network
Topographic maps are based on topographical surveys. Performed at large scales, these surveys are called topographical in the old sense of topography, showing a variety of elevations and landforms. [8] This is in contrast to older cadastral surveys, which primarily show property and governmental boundaries.
A topographical map is the main type of map used to depict elevation, often through 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. Digital terrain models are another way to represent terrain ...
A topographic profile or topographic cut or elevation profile is a representation of the relief of the terrain that is obtained by cutting transversely the lines of a topographic map. Each contour line can be defined as a closed line joining relief points at equal height above sea level. [ 1 ]
Figure 1. This BLM map depicts the principal meridians and baselines used for surveying states (colored) in the PLSS. The following are the principal and guide meridians and base lines of the United States, with the year established and a brief summary of what areas' land surveys are based on each.
A map of Europe using elevation modeling. In its contemporary definition, topographic mapping shows relief. In the United States, USGS topographic maps show relief using contour lines. The USGS calls maps based on topographic surveys, but without contours, "planimetric maps."
The National Map is a significant contribution to the U.S. National Spatial Data Infrastructure (NSDI) from the Federal Geographic Data Committee (FGDC) and currently is being transformed to better serve the geospatial community by providing high quality, integrated geospatial data and improved products and services including new generation ...
Also amphidrome and tidal node. A geographical location where there is little or no tide, i.e. where the tidal amplitude is zero or nearly zero because the height of sea level does not change appreciably over time (meaning there is no high tide or low tide), and around which a tidal crest circulates once per tidal period (approximately every 12 hours). Tidal amplitude increases, though not ...
Elevation measurement: Using fine resolution remote sensing techniques, especially Lidar and drones, to directly or indirectly (through Photogrammetry) measure the height and or shape of land cover features, and shade that elevation surface. This technique is most useful at producing realistic maps at relatively large scales, 1:5,000 to 1:50,000.