source:Industry News release time:2022-08-25 Hits: Popular:realtime gps tracker online
GPS receivers can receive time information accurate to nanoseconds that can be used for timing; forecast ephemeris for forecasting the approximate position of satellites in the next few months; broadcast ephemeris for calculating satellite coordinates required for positioning , with an accuracy of several meters to tens of meters (different for each satellite and changes at any time); and GPS system information, such as satellite status, etc.
The distance from the satellite to the receiver can be obtained by the measurement of the GPS receiver's code. Because it contains the error of the receiver's satellite clock and the error of atmospheric propagation, it is called pseudorange. The pseudorange measured for the 0A code is called the UA code pseudorange, with an accuracy of about 20 meters, and the pseudorange measured for the P code is called the P code pseudorange, with an accuracy of about 2 meters.
The GPS receiver decodes the received satellite signal or uses other techniques to recover the carrier after removing the information modulated on the carrier. Strictly speaking, the carrier phase should be called the carrier beat phase, which is the difference between the carrier phase of the received satellite signal affected by the Doppler shift and the phase of the signal generated by the local oscillation of the receiver. Generally, the measurement is made at the epoch time determined by the receiver clock and the tracking of the satellite signal is maintained, and the phase change value can be recorded, but the initial phase value of the receiver and the satellite oscillator at the beginning of the observation is unknown. The phase integer of the initial epoch is also unknown, that is, the integer ambiguity, which can only be solved as a parameter in data processing. The accuracy of the phase observations is as high as millimeters, but the premise is to solve the ambiguity of the whole circle, so the phase observations can only be used when there is a relative positioning and there is a period of continuous observations, and the positioning accuracy better than the meter level can only be achieved. Phase observations can be used.
According to the positioning method, GPS positioning is divided into single-point positioning and relative positioning (differential positioning). Single-point positioning is a method of determining the position of a receiver based on the observation data of a receiver. It can only use pseudo-range observations and can be used for rough navigation and positioning of vehicles and ships. Relative positioning (differential positioning) is a method of determining the relative position between observation points based on the observation data of two or more receivers. Relative positioning using phase observations.
GPS observations include errors such as satellite and receiver clock errors, atmospheric propagation delays, and multipath effects, and are also affected by satellite broadcast ephemeris errors during positioning calculations. Cancellation or weakening, so the positioning accuracy will be greatly improved. The dual-frequency receiver can offset the main part of the ionospheric error in the atmosphere according to the observations of the two frequencies. ), a dual-frequency receiver should be used.
During positioning and observation, if the receiver moves relative to the surface of the earth, it is called dynamic positioning. Pseudo-range differential positioning with meter-level accuracy, or centimeter-level phase differential positioning (RTK) for measuring stakeouts, etc., real-time differential positioning requires a data link to transmit the observation data of two or more stations together in real time for calculation. During positioning observation, if the receiver is stationary relative to the earth's surface, it is called static positioning. When conducting control network observation, this method is generally used to observe simultaneously by several receivers, which can maximize the use of GPS. Positioning accuracy, receivers dedicated to this purpose are called geodetic receivers and are the best performing class of receivers. At present, GPS has been able to meet the accuracy requirements of crustal deformation observation, and the perennial observation stations of IGS have been able to form a millimeter-level global coordinate frame.
Read recommendations:
3000mAh Magnet Asset GPS Tracker
Last article:GPS positioning accuracy
Next article:Da GPS tells how to prevent car theft
Related Information
Pet GPS Tracker Factory
2023-03-16fleet tracking mobile app
2023-03-16Portable car gps systems
2023-03-16car gps tracker custom
2023-04-11pet gps tracker cat Manufacturing
2023-03-16Magnetic gps tracker sales
2023-04-23Pet GPS Tracker sales
2023-04-11Car gps tracking wholesaler
2023-04-23gps tracker online wholesaler
2023-04-23Car gps tracking distributors
2023-04-23TK200AM-Disposable GPS Tracker
2022-06-214G Wired GPS Tracker PCBA
2022-06-17TK08AL- RFID Car GPS Tracker
2023-10-076000mAh Magnetic Asset GPS Tracker
2025-03-31C32Plus (9~90V E-bikes/Motorcycle/Car gps tracker)
2022-06-21The conversion method of GPS coordinates in unit degrees and seconds
2022-10-12Japan develops global positioning system independently
2022-09-05GPS system space part
2023-02-03Difficulties in GPS indoor navigation
2022-11-03Compared with the difference between vehicle GPS positioning system and mobile phone navigation.real
2023-04-25Three Wiring Route Finding Methods for GPS Positioners
2023-06-27Car GPS has two main uses.Car gps tracking wholesaler
2023-07-20Review of GPS development in the past ten years
2022-12-20gps vehicle tracker.The role of installing car GPS and Beidou satellite positioning in the road tran
2023-10-26Two frequencies can eliminate ionizing layer errors.Portable car gps systems Manufacturing
2023-03-11The difference between the GPS positioner and the navigator
2023-02-25How to install and use the Beidou GPS positioner?gps tracker for trailer Manufacturing
2023-04-14The application and implementation of CAAC BeiDou is divided into three stages.car gps tracker Manuf
2023-06-13A-GPS and GPRS
2022-12-08The manufacturer believes how to effectively prevent the vehicle positioning system from being destr
2023-05-10