a surveying point in germany
surveying helps determine accurately terrestrial or three-dimensional space position of points , distances , angles between them using leveling instruments such theodolites, dumpy levels , clinometers.
work on 1 of first topographic maps begun in france giovanni domenico cassini, great italian astronomer.
even though remote sensing has sped process of gathering information, , has allowed greater accuracy control on long distances, direct survey still provides basic control points , framework topographic work, whether manual or gis-based.
in areas there has been extensive direct survey , mapping program (most of europe , continental us, example), compiled data forms basis of basic digital elevation datasets such usgs dem data. data must cleaned eliminate discrepancies between surveys, still forms valuable set of information large-scale analysis.
the original american topographic surveys (or british ordnance surveys) involved not recording of relief, identification of landmark features , vegetative land cover.
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