is an activity which uses geodetic methods to determine the precise position of number of stations which are distributed over a large area.

two (2) types of control survey that are used in establishing control points

coordinates positional data. These positions can be referenced by parallels or plane coordinate axes. Its main purpose is to establish a network of triangulation stations.

determines the elevation with respect to sea level. Its main objective is to establish a network of reference benchmarks.

It is a method for extending horizontal control for topographic and similar surveys which require observations of triangular figures whose angles are measured and whose sides are determined by trigonometric computations.

It consists of a series of triangles in which one or more sides of each triangle are also sides of adjacent triangles

These are the vertices of the triangles in a triangulation system.

It is one of the lines in a triangulation system whose length is precisely measured and its true direction is determined by astronomical observations. It is usually located at the beginning of the triangulation system and its length is used as the basis for computing the lengths of other lines of the system.

It is one of the lines in a triangulation system whose length is also precisely measured and may be located at regular intervals or at the end of triangulation system. It serves as a check for triangulation computations involving lengths of lines.

It is a method used for horizontal control surveys which is based on measured horizontal distances. It consists of a series of joined or overlapping triangles where sides are measured and the angles are computed.

These are surveys employed to establish geodetic latitudes and longitudes and plane rectangular coordinates of a fundamental networks of reference stations.

These are surveys run by barometric, trigonometric and differential leveling to establish elevations for a network of monuments called benchmarks.

It is the simplest form of triangulation system, however, does not yield to the most accurate results since it lacks certain checks to balance small errors. It involves a minimum number of angular measurements and calculations about the area being considered

It is the most used triangulation system. Each figure is made up of two pairs of overlapping triangles. In each ______ of this type of triangulation system, it should be noted that there is no triangulation station at the intersection of the diagonals.

It is a triangulation system that is composed of a group of triangles in which there is a station at a vertex common to all triangles.

It refers to the selection of suitable pattern for the system and the triangulation stations which would best fit the topography of the area and meet the requirements of the survey

Base lines and angle measurements defined the shape and strength of the triangulation system. The ideal site for a base line should be open, smooth and level ground. In addition, the ends should be intervisible and all possible obstructions are removed.

The stations of a triangulation system should be marked by signals that are visible from the stations from which they are sighted. A signal is a device erected to define the exact position of a triangulation station so that it can be observed from other stations.

It is said that the strength of the triangulation system is dependent on how accurate the angles are measured.

Astronomical observations are done to check accurately the position and directions of stations and lines.

The objective of triangulation computations is to determine the best possible planimetric positions for triangulated stations which are defined by X and Y coordinates. Before the computations, the errors in the field measurements must be eliminated or distributed first.

Proper positioning of stations can be decided using the available topographic maps of the area. From these maps, information can be obtained like ground elevations of the stations, approximate length of lines and character of the intervening terrain.