Four steps of control measurement

A, control measurement (control measurement)

1, purpose and function

(1) Establish a unified plane control network and elevation control network for surveying and mapping or engineering construction.

(2) Control error accumulation.

(3) as a benchmark for various details measurement.

2. Related nouns

(1) small area: it is not necessary to consider the influence range of the curvature of the earth on the horizontal angle and horizontal distance.

(2) Control points: survey datum points with accurate and reliable plane coordinates or elevation.

(3) Control network: a graph composed of distribution of control points and measurement methods.

(4) Control survey: establish the survey work of control network.

3, control measurement classification

(1) According to the content: plane control survey and elevation control survey.

(2) According to accuracy: first-class, second-class, third-class, fourth-class; Level 1, Level 2 and Level 3

(3) According to methods: astronomical survey, conventional survey (triangulation, traverse survey, leveling survey) and satellite positioning survey.

(4) By region: national control survey, urban control survey and small area engineering control survey.