GPS frequency band
1, L1 band -1.57542GHz.
2. L2 band - 1.22760 GHz.
3, L3 band -1.38105 GHz.
4, L4 band -1.81440GHz (expected to start using in 2017).
There are many factors that can affect the accuracy of GPS:
The following is a GPS error introduction profile:
Satellite clock error: 0-1.5 meters
Satellite orbit error: 1-5 meters
Ionospheric introduced error: 0-30 meters
Atmosphere introduced error: 0-30 meters
Receiver's own noise: 0-10 meters
Multiple reflection: 0-1 meters
Total positioning error: about 28 meters
It can be seen that the main GPS positioning error comes from the ionosphere and the atmosphere because the gas molecules in the ionosphere and the water vapor molecules in the atmosphere refract the GPS microwave signal, making it slightly in the route from the satellite to the receiver. Bending causes the receiver to use a curved path as a straight path, introducing errors. This phenomenon is more pronounced when the microwave signal travels obliquely across the ionosphere and the atmosphere because microwave signals travel through it longer and longer.