source:truck tracking webfleet solutions release time:2022-11-18 Hits: Popular:realtime gps tracker online

1.1 Introduction to GPS
GPS (Global Positioning System) is a new generation of satellite navigation, time service and positioning system developed by the United States in the 1970s. Each of the 24 dedicated GPS satellites has its own atomic clock, which can broadcast accurate UTC standard time to the ground 24/7. In the data stream decoded by many universal GPS decoding chips, in addition to location information, it also contains time information (year, month, day, hour, minute, second) and PPS (Pulse Second). PPS identifies the starting point of time information, and its accuracy can reach microsecond level.
1.2 Introduction to timing method
NTP is a protocol used to synchronize computer time. Its synchronization clock source is not limited to the network time server, but also includes clock devices, such as quartz clock, atomic clock, GPS receiver, etc. The NTP server software abstracts these clock sources into corresponding data structures, corresponding to different memory addresses, and synchronizes the computer clock by reading the information in the address and performing statistical algorithm processing.
There are mainly three time calibration schemes using GPS as the synchronous clock source: pulse synchronization mode, serial synchronization mode and integrated mode. The GPSD timing scheme adopted in this paper is a comprehensive way. The comparison of the three methods is shown in Table 1.
1.3 Integrated timing based on GPSD
GPSD (GPS Daemon) is a daemon software used to process the data decoded by the GPS receiving unit. The specific process of GPSD based integrated timing is shown in Figure 1. The GPS antenna receives the GPS signal, transmits it to the G591 chip for decoding, and outputs the data and PPS signal in NMEA0183 protocol format every second. After the MAX 232 completes the level conversion, it transmits them to the computer via the RXD and DCD ends of the serial port respectively; After processing, GPSD software writes accurate time information to specific memory segments; NTP server software reads the time information in this address segment by sharing memory, and then completes the work of correcting the system clock.
Read recommendations:
NB20 -4G Bluetooth Smart Pet Tracker
Design of GPS Vehicle Satellite Positioning Simulation System
Last article:GPS radar detector
Next article:High precision timing system based on GPSD
Related Information
car gps tracker maker
2023-04-234G GPS Tracker manufacturer
2023-04-23fleet gps tracking wholesaler
2023-04-23Dog gps tracker custom
2023-04-11GPS Tracker company
2023-04-11vehicle gps tracker webfleet solutions
2023-03-16car gps tracker manufacturer
2023-04-23GPS Trackers sales
2023-04-11mini gps tracker maker
2023-04-23car gps tracker sales
2023-04-23G05N Vehicle Tracker
2022-06-21NB20 -4G Bluetooth Smart Pet Tracker
2022-06-21G06L- 4G Car GPS Tracker
2022-09-06TK100B- Accurate Pro version GT06/TK100
2023-10-06G08L - 4inch Smart Tail Light Tracker
2022-06-20How to apply GPS positioner to view the location of the electric vehicle
2023-03-06The method of using GPS receiver in the field
2022-11-2650 fire trucks are equipped with GPS global positioning and navigation system
2022-08-24Application of GPS
2022-09-24Why can't the indoor GPS positioning cannot be achieved.fleetmanagement webfleet solutions
2023-02-24The development of GPS system
2022-10-12GPS predecessor
2023-06-01The future of smartphone GPS application
2022-10-10Internationally leading GPS navigator.gps tracker with magnet manufacturer
2023-08-26GPS transmission network.Hidden GPS Trackers Solution
2023-07-10Talk about the advantage of the use of pet smart positioner.realtime gps tracker online manufacture
2023-03-10Gps speed limiter.Handheld GPS jammer
2023-11-15Introduction to GPS Platform
2022-11-09Main indicators and characteristics of GPS monitoring and scheduling system.obd-II port gps tracker
2023-08-11GPS classification and usage.gps vehicle tracker company
2023-07-14