source:Industry News release time:2022-11-02 Hits: Popular:realtime gps tracker online

The basic principle of GPS navigation system is to measure the distance between the known position of the satellite and the user's receiver, and then integrate the data of multiple satellites to know the specific position of the receiver. To achieve this, the position of the satellite can be found in the satellite ephemeris according to the time recorded by the onboard clock. The distance between the user and the satellite is obtained by recording the time the satellite signal travels to the user and multiplying it by the speed of light (due to the interference of the ionosphere of the atmosphere, this distance is not the real distance between the user and the satellite, but the pseudoran distance (PR) : When the GPS satellite is working properly, it will continuously send navigation messages using pseudo-random codes (pseudo-codes) composed of 1 and 0 binary symbols. There are two types of pseudocodes used in GPS systems, namely C/A code for civilian use and P(Y) code for military use. C/A code frequency 1.023MHz, repetition period of one millisecond, code spacing of 1 microsecond, equivalent to 300m; The P code frequency is 10.23MHz, the repetition period is 266.4 days, and the code spacing is 0.1 microseconds, which is equivalent to 30m. And Y code is formed on the basis of P code, the secrecy performance is better. Navigation messages include satellite ephemeris, working conditions, clock correction, ionospheric delay correction, atmospheric refraction correction and other information. It is modulated from the satellite signal and transmitted at 50b/s modulated on the carrier frequency. Each main frame of a navigation message contains 5 sub-frames, each 6s in length. The first three frames are 10 characters each; Repeat every 30 seconds and update every hour. The last two frames total 15000b. The content of navigation message mainly includes telemetry code, conversion code, data block 1, 2 and 3, among which the most important is ephemeris data. When the user receives the navigation message, the distance between the satellite and the user can be obtained by extracting the satellite time and comparing it with his own clock. Then the satellite ephemeris data in the navigation message can be used to calculate the position of the satellite when the message is sent, and the position and velocity of the user in the WGS-84 geodetic coordinate system can be obtained.
Read recommendations:
Last article:Domestic GPS Function
Next article:What are the main characteristics of GPS technology?
Related Information
fleet gps tracking Production
2023-04-23truck tracking webfleet solutions
2023-03-16Car gps tracking price
2023-04-11GPS Tracker sales
2023-04-11fleet solution webfleet solutions
2023-03-16mini gps tracker Vendor
2023-04-23rastreador de GPS
2023-03-16GPS Tracking Solution
2023-04-11gps vehicle tracker company
2023-04-11fleet gps trackers wholesale
2023-04-23NB20 -4G Bluetooth Smart Pet Tracker
2022-06-21G500L -4G OBD GPS Tracker
2022-09-06G900LS 8 Lines-4G Car GPS Tracker
2025-03-31TK08AL- RFID Car GPS Tracker
2023-10-07G183 serials -JOBD GPS Tracker
2022-09-06Three wiring line search methods for installing GPS positioner.realtime gps tracker online supplier
2023-04-11How GPS Location Trackers Work
2022-07-07The significance of GPS positioning technology in the construction machinery industry.obd2 gps track
2023-03-16GPS positioning principle
2022-11-26How accurate is GPS positioning?
2022-10-28What is the best type of strong magnetic wireless car GPS locator?fleet gps tracking
2023-09-05GPS positioning system prospects
2023-06-02Two Point Application of GPS.obd2 gps tracker verizon manufacturer
2023-08-01Features and functions of in car GPSD
2023-07-27GPS signal acquisition unit
2022-11-10The working principle and equipment composition of the GPS positioning management system.obd-II port
2023-05-06mini gps tracker.Can car GPS locators be installed on motorcycles
2023-10-24Introduction to GPS in Wildlife Protection.obd2 gps tracker verizon manufacture
2023-05-06Timing method of GPS synchronous clock
2022-11-18GPS early warning device
2023-06-02