source:truck tracking webfleet solutions release time:2023-08-19 Hits: Popular:realtime gps tracker online
After the Soviet Union launched the first artificial satellite, researchers at the Applied Physics Laboratory of John Hobbs King University in the United States proposed that since the position of the observation station could be known, if the satellite position was known, it should also be possible to measure the recipient's location. This is the basic idea of navigation satellites. The basic principle of a GPS navigation system is to measure the distance between a satellite with a known position and the user's receiver, and then combine the data of multiple satellites to determine the specific position of the receiver. To achieve this goal, the position of the satellite can be found in the satellite ephemeris based on the time recorded by the onboard clock. The distance from the user to the satellite is obtained by recording the time it takes for the satellite signal to propagate to the user, and then multiplying it by the speed of light (due to interference from the atmospheric ionosphere, this distance is not the true distance between the user and the satellite, but pseudo-random code (PR): When the GPS satellite is operating normally, it will continuously transmit navigation messages using a pseudo-random code composed of 1 and 0 binary symbols (referred to as pseudo-random code). There are two types of pseudo codes used in GPS systems, namely civilian C/A codes and military P (Y) codes. The C/A code frequency is 1.023MHz, with a repetition period of one millisecond and a code spacing of 1 microsecond, equivalent to 300m; The P-code frequency is 10.23MHz, with a repetition period of 266.4 days and a code spacing of 0.1 microseconds, equivalent to 30m. The Y code is formed on the basis of the P code, which has better confidentiality performance. Navigation messages include satellite ephemeris, operating conditions, clock correction, ionospheric delay correction, atmospheric refraction correction, and other information. It is emitted on the carrier frequency at 50b/s {A | zh cn: modulation; zh tw: modulation from satellite signals. The navigation message contains 5 subframes in each main frame, with a frame length of 6 seconds. The first three frames each have 10 character codes; Repeat every thirty seconds and update every hour. The last two frames total 15000b. The content in navigation messages mainly includes telemetry codes, conversion codes, 1st, 2nd, and 3rd data blocks, with the most important being ephemeris data. When a user receives a navigation message, the satellite time is extracted and compared with their own clock to determine the distance between the satellite and the user. Then, the satellite ephemeris data in the navigation message is used to calculate the position of the satellite when transmitting the message. The user's position and velocity in WGS-84 {A | zh cn: geodetic coordinate system; zh tw: geodetic coordinate system} can be obtained. It can be seen that the function of the satellite part of the GPS navigation system is to continuously transmit navigation messages. However, due to the fact that the clock used by the user's receiver cannot always be synchronized with the satellite's onboard clock, in addition to the user's three-dimensional A | zh cn: coordinates; zh tw: coordinates} - x, y, z, we also need to introduce a Δ The time difference between the satellite and the receiver is taken as an unknown number, and these four unknowns are solved using four equations. So if you want to know the location of the receiver, you need to be able to receive signals from at least four satellites.
Read recommendations:
The advantages of remote anti -theft of electric vehicle GPS positioner
The strategic role of GPS satellite positioning system and commercial interests.gps tracker no month
Last article:The implementation of the PS plan is divided into three stages.plug & play Obd gps tracker whole
Next article:GPS composition.gps tracker no monthly fee manufacture
Related Information
gps tracker for kids
2023-03-16Dog gps tracker Vendor
2023-04-23GPS Tracking custom
2023-04-11gps tracker fur auto webfleet solutions
2023-03-164G GPS Tracker sales
2023-04-23portable gps tracker Vendor
2023-04-23plug & play Obd gps tracker
2023-04-23GPS Tracker company
2023-04-11Gps speed limiter company
2023-04-23mini gps tracker price
2023-04-23G200NY -Cow/Camel GPS Tracker
2022-06-21G900LM-4G Car Mini GPS Tracker
2025-03-25G05N Vehicle Tracker
2022-06-21Mini Sized GPS Tracker PCBA
2022-06-17TK100 (GT06) Vehicle Tracker
2022-06-20Introduce the different types of the positioner
2023-03-07What does GPS navigation system mean?
2022-08-05car GPS global positioning system
2022-09-05Differences between GPS monitoring platform BS and CS
2022-12-14GPS positioner manufacturer compare which accuracy of Beidou and GPS positioning is higher.obd2 gps
2023-05-06Composition of GPS PXI acquisition equipment system
2022-11-11The development of electronic maps.personal gps tracker Manufacturing
2023-05-17Can the GPS positioning system help the breeding industry save costs?
2023-02-22The conversion method of GPS coordinates in unit degrees and seconds
2022-10-11GPS system functions
2022-11-09The Development of China's GPS Navigation Market.gps tracker for trailer manufacturer
2023-08-25Gps speed limiterDoes the ultra small button type GPS locator exist
2023-10-24The application processor completes the GPS/Galileo function
2022-10-15Troubleshooting the cause of vehicle GPS locator offline and intermittent data.4G GPS Tracker
2023-09-21Car GPS Navigation System Operation
2022-11-04