source:Industry News release time:2022-07-08 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. Can offset or weaken, 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:
portable gps tracker distributors
G01 Smallest Personal Old People Mini GPS Tracker for Kids
Schematic diagram of GPS satellite navigation system
The car GPS positioner plug -in card is still free of card.van tracker webfleet solutions
Last article:What is the difference between a car GPS locator and GPS navigation?
Next article:How GPS Location Trackers Work
Related Information
Car gps tracking manufacturer
2023-04-23real-time gps tracking price
2023-04-23GPS Trackers price
2023-04-11car gps tracker Manufacturing
2023-04-23mini gps tracker Manufacturing
2023-04-23real-time gps tracking Processing
2023-04-23mini gps tracker
2023-04-11pet gps tracker cat
2023-03-16car gps tracker price
2023-04-11car gps tracker price
2023-04-233 Years Disposable Asset GPS Tracker
2025-03-31TK08A Motorcycle GPS Tracker
2022-06-20G01 Smallest Personal Old People Mini GPS Tracker for Kids
2022-06-19TK100N- Multi functional GPS Tracker
2023-10-06G500M-Mini GPS Tracker
2022-06-20GPS common signal location
2022-09-28The advantages and disadvantages of the flat antenna of the GPS vehicle positioning terminal
2023-04-06WIFI positioning of gps tracker is not necessarily the most accurate
2022-07-15China Beidou Navigation System?
2022-11-17The manufacturer summarizes the main application scope of Xi'an's long standby GPS.obd2 gps tracker
2023-04-08Gps speed limiter.The significance of installing GPS system in vehicle safety management
2023-10-28GPS selection.Hidden GPS Trackers wholesale
2023-06-28Main Errors in GPS Positioning and Their Elimination Algorithm
2022-12-10Advantages of traditional GPS and new technology GPS solutions
2022-10-15What are the key points for purchasing in car GPS.personal gps tracker Solution
2023-06-16Independent GPS.fleet gps tracking wholesale
2023-07-05Type of GPS data format and extraction of positioning information
2022-11-24GPS navigation phone.portable gps tracker Solution
2023-06-07GPS positioning manufacturers introduce the composition of satellite positioning systems.Dog gps tra
2023-06-14GPS reference station subsystem.Magnetic gps tracker supplier
2023-07-03