1. What is the meaning of the 20 channels of the GPS module?
The GPS module has a parameter of the number of channels, for example, 20 channels, which means that the module can establish communication with 20 satellites at the same time, 3 satellites are 2D positioning, data is unstable, and the module only receives more than 3 satellite signals at the same time. After complicated calculations, the correct positioning data can be obtained. If the number of satellites communicating at the same time is more, the module can obtain the positioning data more quickly and accurately. In the general urban environment on the surface of the earth, it can usually be 4~11 at the same time. Satellite simultaneous communication.
2. Why does the GPS module take a long time to get the positioning data after booting?
The GPS module has cold start, hot start and warm start (the current technology has basically made the cold start and warm start two mode parameters very close, thus gradually canceling the warm start) three parameters, if the GPS module is first powered , or when the power is turned on after more than 500 kilometers, the module needs to recalculate the ephemeris data. Generally, the GPS module normally takes more than 30 seconds to normal positioning (this is the cold start), and the S-87 has a built-in button battery. The ephemeris data can be stored inside the module. When the next module works, it can be positioned very quickly. Generally, the S-87 only needs 1~3 seconds to realize the new positioning. The positioning is called hot start. If the module is powered off for more than 4 hours and the internal RTC is not powered in real time, then another boot is equivalent to a cold boot.