A geodetic datum is an abstract coordinate system with a reference surface (such as sea level) that serves to provide known locations to begin surveys and create maps. When it is completed, users will be able to get accurate heights to within about an inch for most locations around the nation. Near coastal areas, mean sea level (and other tidal datums) is determined by analyzing observations from a tide gauge. This model originally took life as the National Geodetic Vertical Datum of 1929. currently uses the North American Vertical Datum of 1988, or NAVD 88. There are two main datums in the United States.ĭatums are the basis for all geodetic survey work. Generally speaking, there are datums in the realm of a design and construction project that are very charged with relevance in terms of land use regulations. While the earth ellipsoid is used for most situations, geoid models are conducted on a more local level. Geodesists and surveyors use datums to create starting or reference points for floodplain maps, property boundaries, construction surveys, levee design, or other work requiring accurate coordinates that are consistent with one another. Such a legal description might include 溾€eginning at the intersection of the eastern boundary of the Columbia River and the southwesterly corner of the State of Oregon︹€? If, for example, the datum for an area is a point 100 feet. In today real estate world, the most common use of a datum is found in a metes and bounds legal description of a property. A surveyor uses a datum as an official elevation point to describe the height or depth of a property. Artificial horizontal plane of elevation People also ask Real Estate Glossary Term Datum Line A horizontal line from which heights and depths are measured.
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