In
geodesy and
surveying a
control network or simply
control, is a set of reference-points of known
geospatial coordinates. The higher-order (high precision, usually millimeter-to-decimeter on a scale of continents) control points are normally defined in both space and time using global or space techniques, and are used for "lower-order" points to be tied into. The lower-order control points are normally used for
engineering,
construction and
navigation. The scientific discipline that deals with the establishing of coordinates of points in a high-order control network is called
geodesy, and the technical discipline that does the same for points in a low-order control network is called
surveying.