English

A STATION artificially marked by well defined natural or artificial objects, whose GEOGRAPHIC POSITION has been accurately determined and which has been described.

A place where tide or tidal current constants have been determined from OBSERVATIONS, and which is used as a STANDARD for the comparison of simultaneous OBSERVATIONS at a SUBORDINATE STATION. It is also a place for which independent daily predictions are given in the tide or tidal current tables, from which corresponding predictions are obtained for other locations by means of differences or factors. Also called standard station and standard port (British terminology).

One of the places for which tide or tidal current predictions are determined by applying a CORRECTION to the predictions of a REFERENCE STATION. A tide or tidal current station at which a short series of OBSERVATIONS was made and reduced by comparison with simultaneous OBSERVATIONS at a REFERENCE STATION. Called secondary port in British terminology. See STATION: TIDE.

An auxiliary STATION, es­tablis­hed to increase the number of CONTROL STATIONS in a given area, or to place a STATION in a desired locati­on where it is impracticable or unnecessary to esta­blish a principal STATION. Also called secondary stati­on.

A place where TIDAL OBSERVATIONS are obtained. It is a primary tide station when continuous OBSERVATIONS are available for a sufficient number of years to determine the characteristic tide features for the locality. A secondary tide station is operated during a short period of time to obtain DATA for a specific purpose.

A definite point on the EARTH, whose GEOGRAPHIC POSITION has been determined by gra­phic methods, usually by PLANE TABLE TRAVERSE or gra­phic TRIANGULATION. Also a point located by geode­tic methods but with less than third-order ACCURACY.

A definite point on the EARTH whose POSITION has been determined from another known point by linear measurements con­trolled in AZIMUTH by angu­lar measurements.

A recoverable point on the EARTH, whose GEOGRAPHIC POSITION has been determined by angular methods with geodetic instruments. A triangulation station is a selected point, which has been marked with a STATION MARK, or it is a conspicuous natural or artificial object. Also called trigonometric station or triangulation point.

A TRIANGULATION STATION that cannot be found and cannot be included in the TRIANGULATION to connect it with a new DATUM. Sometimes called 'lost' station.

A theory which assumes that the basic tide motion in the open OCEAN consists of a system of STANDING WAVE oscillations; PROGRES­SIVE WAVES are of secondary importance except where the TIDE advances into tributary waters.

A BUOY used to mark the approximate POSITION of an important BUOY or LIGHTSHIP should it be carried away or temporarily removed. Also called MARKER BUOY, watch buoy.

A buried mark-stone, a metal plug or disk, or any kind of permanent MARK intended to provide a means of re-identifying main CONTROL STATI­ONS. See SURFACE MARK and UNDERGROUND MARK.