GPS Global Positioning System (GPS) is a new satellite positioning system developed by modern society. It mainly uses the ground GPS receiver to accept 24 satellite signals distributed over the earth, thus realizing real-time, Reliable and effective information such as 3D position and time. The basic principle of GPS positioning is based on the instantaneous position of the satellite moving at high speed as the known starting data, and the method of spatial distance resection is used to determine the position of the point to be measured.
There are many shortcomings in GPS navigation applications. While enjoying the convenience brought by GPS navigation, people often complain that GPS often sends wrong navigation commands when driving on overpasses and elevated roads. For example, when driving normally on the bridge, the GPS suddenly calls you to turn right, but there is no right-turning exit on the bridge. This is because the GPS receiver does not accurately determine whether the vehicle is actually on the bridge or under the bridge, thus issuing an error. Instructions. The altitude error calculated by the current GPS receiver is basically several tens of meters, and some GPS receivers do not even display the altitude value. In view of the fact that the GPS receiver is not accurate enough to measure indoors outdoors, the integrated pressure sensor in the mobile phone calculates the actual altitude of the GPS receiver using the correspondence between air pressure and altitude.Pressure sensors and GPS receivers get accurate height information. At present, GPS sensors on the market are rarely equipped with pressure sensors. In fact, high-precision pressure sensors can also be widely used in GPS receivers.