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:
obd2 gps tracker verizon wholesaler
Last article:GPS positioning accuracy
Next article:Da GPS tells how to prevent car theft
Related Information
mini gps tracker maker
2023-04-23Cantrack TK100
2023-03-16pet gps tracker cat wholesaler
2023-03-16OBD GPS Tracker
2023-04-11car gps tracker sales
2023-04-23real-time gps tracking wholesale
2023-04-23simple gps tracking Factory
2023-04-23Gps speed limiter Factory
2023-04-23gps tracker für auto supplier
2023-04-23pet gps tracker cat supplier
2023-03-16YG119- Hunting Dog GPS tracker
2023-10-07G05N Vehicle Tracker
2022-06-21G06L
2022-06-21G200(L) -Magnet GPS Tracker
2022-06-204G Wired GPS Tracker PCBA
2022-06-17Vehicle GPS positioning management system
2022-11-04What is GPS location time?
2022-10-28GPS signal in the air
2022-11-08Car GPS positioning system.portable gps tracker Vendor
2023-05-26GPS Modules and Products
2022-08-19GPS monitoring information platform ensures smooth traffic
2022-12-17Development of China's GPS Navigation Market
2022-09-26The combination of GPS and GIS.realtime gps tracker online wholesaler
2023-05-06GPS system management
2022-10-08How to judge the quality of a car GPS locator?vehicle gps tracker webfleet solutions
2023-03-21Type of GPS data format and extraction of positioning information
2022-11-24GPS elevation application.pet gps tracker cat company
2023-07-21Real time monitoring of police cars by GPS positioning
2022-12-17Can the car GPS locator be used indoors and underground parking lots?realtime gps tracker online Man
2023-03-25GPS development in the United States
2022-11-24