By adjusting the three-dimensional baseline vector obtained by GPS relative positioning through GPS network, the high-precision geodetic height based on WGS-84 ellipsoid can be obtained. The height system adopted in China is a normal height system based on quasi-geoid, and the traditional geometric leveling or trigonometric leveling method is the main means to obtain the normal height based on quasi-geoid.
By finding the mathematical expression of the gap between quasi-geoid and ellipsoid (quasi-geoid model), GPS geodetic height can be converted into normal height, so that GPS altimetry can replace high-precision geometric leveling or trigonometric leveling.
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Application of Global Positioning System
Application of 1 in road engineering
The application of GPS in road engineering is mainly used to establish various road engineering control networks and determine the external control points of aerial survey. With the rapid development of high-grade highways, higher requirements are put forward for survey technology. Because of the long line and few knowledge points, it is not only difficult to lay out the network with conventional measurement methods, but also difficult to meet the requirements of high precision.
2. Patrol application
GPS is the abbreviation of English GlobalPositioningSystem. The advantage of applying GPS to electronic patrol is that if there is no need to install patrol points on long and far patrol lines, coordinate signals can be obtained directly from satellites, which is mainly suitable for long-distance patrol inspections such as telecommunications, forest fire prevention and petrochemical oil and gas pipeline exploration.
3. Vehicle tracking
Using GPS and electronic map, the actual position of the vehicle can be displayed in real time, and can be enlarged, reduced, restored and changed at will. Can move with the target, so that the target always stays on the screen; But also can realize simultaneous tracking of multiple windows, multiple vehicles and multiple screens. This function can be used to track and transport important vehicles and goods.
Baidu encyclopedia-global positioning system
Baidu Encyclopedia-Dadigao