控制测量学是研究精确测定和描绘地面控制点空间位置及其变化的学科。它是在

It is the study of the control measurements and precise determination of the spatial position of the ground control points drawing and variations thereof of the subject. It is a construction and engineering survey work to ensure social security and war is the main target in the development and form the theoretical basis of Geodesy on the basis of human social activity columns provide useful spatial information. Therefore, in essence, it is geo-engineering information science, is an important branch of geoscience and mapping science is the basis of measurement engineering disciplines, but also applied science. It plays an important role in professional training measurement project. Control measurement services mainly all kinds of construction, urban construction and land planning and management. This determines its measurement range geodetic smaller, and also has a variety of features on the observation means and the data processing method. <br>E.g. elevation control accuracy of the measurement task is predetermined by the tunnel entrance Surveying (including import and export of a tunnel, shaft opening, peace Oblique wellhead ring opening) close to the standard point elevation, elevation primer as measured according to the hole. Height control method usually three, four, etc. Leveling Surveying. Leveling should choose the most flat connecting hole and the shortest lines, station set to achieve a small, fast observed, high accuracy requirements. Each hole is buried level not less than two points, and arranged to measure a water level appropriate to linking. Greater than 1KM, should be added to the standard points temporary intermediate distance between both ends of the hole.

Control measurement is the study of the precise determination and description of the ground control point space position and its changes. It is developed and formed on the basis of geodesy with engineering construction and the measurement work of social war and security assurance as the main service object, and provides useful spatial information for social activities. Therefore, in essence, it is the subject of geoengineering information, an important branch of geosciences and surveying, the basic discipline in engineering construction measurement, and also the applied discipline. In the measurement engineering professional training occupies an important position. The object syings of control measurement are mainly various engineering construction, urban construction and land planning and management. This determines that its measuring range and geodesy are small, and it is also diverse in observation and data processing methods.<br> For example, the task of elevation control measurement is to measure the elevation of the horizontal point near the tunnel hole (including the import and export of the tunnel, the shafthead, the oblique wellhead and the peace head) according to the prescribed precision, as the basis for the elevation to guide the hole into the hole. Elevation control is usually measured by three or four levels of measurement. Level measurement should choose the smoothest and shortest line connecting the hole, in order to meet the requirements of less station, fast observation and high precision. Each hole should be buried at no less than two level points, and to place a level can be jointly measured. When the distance between the openings at both ends is greater than 1KM, a temporary level point should be added in the middle.

Control surveying is a subject that studies the precise measurement and description of the spatial position and change of ground control points. Based on the basic theory of geodesy, it is developed and formed with engineering construction, social war and safety assurance survey as the main service object, providing useful spatial information for the social activities of the people's train. Therefore, in essence, it is a discipline of geoengineering information, an important branch of Geoscience and surveying, a basic discipline in engineering construction survey and an applied discipline. It plays an important role in the training of measurement engineering talents. The service objects of control survey are mainly various engineering construction, urban construction and land planning and management. This determines that its measurement range and Geodesy should be small, and it also has a variety of characteristics in observation means and data processing methods.<br>For example, the task of elevation control survey is to measure the elevation of the benchmark near the tunnel portal (including the entrance and exit of the tunnel, the vertical wellhead, the inclined wellhead and the ring mouth) according to the specified accuracy, as the basis for elevation leading into the tunnel. Elevation control usually adopts the third and fourth order leveling method. In order to meet the requirements of less stations, fast observation and high accuracy, the most flat and shortest line connecting the portal shall be selected for leveling. There shall be no less than two benchmarks buried in each hole, and it is advisable to place a level gauge for joint measurement. When the distance between the holes at both ends is more than 1km, temporary benchmarks shall be added in the middle.<br>