English

As applied to electronics, any transmitted electrical IMPULSE. That which conveys intel­ligence in any form of commu­nication, such as a TIME SIGNAL, a PIP on the SCOPE of electronic equipment, or an object marking the locati­on of a surveying STATION.

A sign indicating a time event, observable at different stations, and used in compa­ring LOCAL TIMES of those stations, and determin­ing the difference of their LONGITUDES.

A natural or artificial object or struc­ture whose horizontal and sometimes vertical POSITION is obtained by surveying methods. Survey signals are given special designation according to the kind of SURVEY in which they are determined, or which they may later serve.

An accurate SIGNAL marking a specified TIME or time interval. It is used primarily for deter­min­ing ERRORS of TIMEPIECES. Such SIGNALS are usually sent from an observatory by RADIO, but visual SIGNALS are used at some PORTS.

A rigid structure erected close or over a TRIANGULATION STATION. Also any object, natural or artificial, whose POSITION is obtained in a triangulation survey. The term may be applied to a structure whose POSITION is determined by TRIANGULATI­ON, but whose primary purpose is to serve later in a HYDRO­GRAPHIC or TOPOGRAPHIC SURVEY, when it may become known as a HYDROGRAPHIC or TOPOGRAPHIC SIGNAL.

A three-legged TRIANGULATION SIGNAL. It is usually constructed in such a manner that an obser­ver can set up his THEODOLITE and make OBSERVA­TIONS without moving any of the structure.