Application characteristics of satellite positioning and navigation technology

(1) is widely used. It can be used for sea and air navigation, vehicle guidance, missile guidance, precise positioning, dynamic observation, speed measurement and time measurement on a global scale. It has a wide range of applicability in surveying and mapping, environmental change and disaster monitoring, such as reconstruction and encryption of geodetic network, monitoring of subsidence and deformation in mining areas, photogrammetry and remote sensing without ground control, positioning measurement of engineering construction, etc.

(2) Fast observation speed and high efficiency. The field work time is short and the intensity is low. One station can observe 5 ~ 8 satellites at the same time. If fast positioning software is used, the accuracy of (5mm+ 10-6)D can be obtained in a few minutes by static phase positioning of dual-frequency receiver. When necessary, it can also realize automatic data transmission and communication.

(3) High positioning accuracy. The practice shows that the relative positioning measurement accuracy of GPS is very high, and the internal and external coincidence accuracy is in line with the nominal accuracy of (5mm+ 10-6)D, in which the plane position accuracy is quite good, but the height difference is less. According to the positioning measurement results, the distance and orientation of the two stations are calculated with good accuracy. A large number of experimental results show that the relative positioning of short distance (within 15km) can reach centimeter level or even higher.

(4) High economic benefits. Because satellite positioning does not require inter-station visibility, it is not necessary to establish a time-consuming, laborious and expensive target, and the cost of completing similar measurements is less than that of conventional methods 1/2 ~ 2/3.

(5) The combination or integration of GPS and various technologies can be realized. The combination or integration of GPS and other technologies will make its functions and functions more powerful. For example, the combination of GPS and inertial navigation system is used for vehicle navigation or improving the reliability and accuracy of geodetic positioning, the combination of GPS and electronic map is used for vehicle monitoring and management of public security, insurance and other rescue systems, and the combination of GPS and CCD camera is used for rapid ground survey and monitoring. The combination of GPS and DTM (Digital Terrain Model) is used in the design and construction management of mines or traffic engineering. RTKGPS and total station form an omni-directional measurement workstation, and GPS and various detection instruments form a variety of automatic real-time underground, underwater and air monitoring systems.