source:truck tracking webfleet solutions release time:2024-03-04 Hits: Popular:realtime gps tracker online
Roughly speaking, the ground coordinates and their conventional geographic features (i.e. spatial resection) are obtained by measuring the distance from an in orbit satellite (which determines it to be a known data) to a ground point. Because the position variables in the equation include XYZ and clock deviation T, the number of accepted satellites must be greater than or equal to 4.
In the positioning process, there are two methods to obtain the pseudorange (i.e. the distance with errors) from the satellite to the ground: 1. ranging code; 2. Carrier phase.
1. The ranging code belongs to pseudo-random noise code, which is a binary code sequence. The key is to measure the time difference between the transmitted signal and the received signal, which is obtained through atomic clock synchronization. Due to the refraction of the carrier wave carrying the ranging code when passing through the current layer, ionospheric errors are generated. Solar activity has an impact on the total electron density of the ionosphere, so it can also have an impact on GPS positioning. According to our teacher, there was a period of time when GPS could not be used due to solar flares.
2. If a satellite S emits a carrier model (which is used as a ranging signal here), the signal propagates to various places. At a certain moment, the phase of the signal at receiver R is ψ R. At satellite S ψ S. Note that what is mentioned here is ψ R, ψ S is the complete carrier phase, including the entire number of cycles, calculated from the same starting point. The distance between the satellite and the ground ρ=λ ( ψ S- ψ R) .
As can be seen from the above, if the corresponding phase number is inaccurate or cannot be directly obtained, then GPS will not work. In addition, during the measurement process, if the altitude angle of the satellite (the angle between the satellite and the ground level) is too small, it is also impossible to perform measurement and positioning. In summary, during the measurement period, there were no four or more satellites, the altitude angle was too small, there were obstructions such as high-rise buildings, intense solar activity, the position and operation of satellites in orbit, and the condition of the receiver may all cause GPS to be unable to locate or inaccurate.
Read recommendations:
G08L - 4inch Smart Tail Light Tracker
Last article:Gps speed limiter.Working principle of GPS Bluetooth positioning technology
Next article:GPS Tracker.Application of GPS module
Related Information
real-time gps tracking distributors
2023-04-23mini gps tracker sales
2023-03-16best gps tracker
2023-04-11Gps speed limiter wholesale
2023-04-23obd2 gps tracker verizon
2023-04-11GPS Tracker Vendor
2023-04-11Gps speed limiter Production
2023-04-23gps vehicle tracker price
2023-04-11gps vehicle tracker manufacturer
2023-04-23mini gps tracker manufacturer
2023-04-23G09L -6 inch Tail light tracker
2022-06-20G900LM-4G Car Mini GPS Tracker
2025-03-25G07L 4G GPS Tracker
2022-09-06GF70L-Solar Magnetic Asset GPS Tracker
2023-10-07G500M-Mini GPS Tracker
2022-06-20The basic architecture and characteristics of GPS
2022-10-15The manufacturer introduced in detail what applications of GPS in aviation flight navigation.gps tra
2023-04-25How to do car GPS positioning in a car rental company.obd2 gps tracker verizon distributors
2023-03-16The correct way to use a GPS receiver in the field
2022-08-16The method of using GPS receiver in the field
2022-11-26GPS positioner helps logistics and transportation companies manage transparency and intelligence.obd
2023-03-28GPS monitoring system system function and characteristics
2023-02-11The application process of GPS positioner in car loans is as follows.vehicle gps tracker Manufacturi
2023-03-17GPS signal acquisition unit
2022-11-10GPS navigation satellite has a high-precision atomic clock for time service
2022-12-29The manufacturer believes what application scenarios are there in the Beidou GPS positioner.gps trac
2023-05-12How should a car loan company choose a reasonable car GPS locator?obd2 gps tracker verizon
2023-03-24The significance of GPS monitoring and scheduling system.realtime gps tracker online wholesaler
2023-08-07Considerations for choosing a gps tracker
2022-09-13Troubleshooting the cause of vehicle GPS locator offline and intermittent data.4G GPS Tracker
2023-09-21