Station Definitions for Land Surveyors

station-1 A definite point on the Earth whose location has been determined by surveying methods. Usually, but not always, marked on the ground using a monument of special construction, or by a natural or-artificial structure. The station’s origin or purpose is usually described in its name. 2 Any point whose position is given by its total distance from the starting hub; also, each stake set at 100-foot intervals along a route survey.

station, astronomic—A point on the Earth whose position has been determined by observations of heavenly bodies.

station, control—See control station.

station, eccentric—A survey point over which an instrument is centered and observations are made, which is not in the same vertical line with the station which it represents, and to which the observations will be reduced before being combined with observations at other stations. An eccentric station may be established and occupied when it is impractical to occupy the station center, or when it becomes necessary to see points which are not visible from the station center. See also reduction to center.

station, instrument—A station at which a surveying instrument is set up for making measurements.

station, intersection—An object whose horizontal position is determined by observations from other survey stations, no observations being made at the object itself. Where the object is observed from only two stations, the position is described as a “no-check position” as there is no proof that such observations are free from blunders. Intersection stations are either objects which it would be difficult to occupy with an instrument, or survey signals whose positions can be determined with sufficient accuracy without being occupied.

station, Laplace—A triangulation or traverse station at which a Laplace azimuth is determined. At a Laplace station, both astronomic longitude and astronomic azimuth are determined. See also azimuth, Laplace; Laplace control.

station, main-scheme—One of the principal stations of a triangulation arc or net tht is observed, computed, and adjusted in accordance with the general specifications for the project, and contributing to the overall strength of the system.

station, primary—See station, main-scheme.

station, principal—A station through which basic data are carried in the extension of a survey system. Also known as “main-scheme station.” A principal station serves primarily for the continued extension of a survey. This requires an order of accuracy and precision in its determination higher than if its purpose were limited to the control of local surveys or the establishment of supplementary stations.

station, resection—A station located by resection methods.

station, recovery of—To visit a survey station, identify its mark as authentic and in its original location, and verify or revise its description. Examples of the type or nature of the recovery are recovered bench mark, or a recovered triangulation station.

station, secondary—A survey station established in conjunction with the main-scheme station, but observed with a lower order of accuracy and precision, to increase the density of control or to provide additional control stations in the area. It does not usually contribute to the general strength of the control and is not included in the main-scheme adjustment.

station, secondary tide—A place at which tide observations are made over a short period to obtain data for a specific purpose.

station, subsidiary—A station established to overcome a local obstacle to the progress of a survey, and not to determine position data for the station point. This term is usually applied to A-stations of a traverse survey. Subsidiary stations are usually temporary in character and not permanently marked. If serving the additional purpose of supplying control for a local survey, such a station may be permanently marked; it is then a supplementary station.

station, supplementary—See station, subsidiary.

station, tide—A place at which tide observations are taken.

station adjustment—The adjustment of angle measurements at a triangulation or traverse station to satisfy local requirements (such as horizon closure) without regard to observations or conditions at other points.

station elevation-1 The actual elevation or the assumed elevation of a station marker from which other elevations are measured or to which the elevations of other points are related. 2 The elevation above sea level for a station used by the U.S. Weather Bureau as the basis to which all pressure observations at the station correspond.

station error—See deflection of the plumb line.

stationing—Setting stakes at specified intervals along a route survey, commencing at the starting hub. Full stations are set at 100-foot intervals. A stake set at a point 50 feet from a full station is known as a “half station.”

station mark—See mark (definition 2).

station marker-1 A permanent mark, usually a depression or a cross in a metal disk adhering to a man-made (constructed structure, concrete post or cylinder, or corrosion resistant pipe or rod) or natural (boulder or rock outcrop) feature, the position of which is expected to remain fixed. 2 A tack, nail, or other mark in a wooden hub or other holder to identify, temporarily and for current use, the position of a station.

Source: NSPS “Definitions of Surveying and Related Terms“, used with permission.

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