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:
What should I do if I encounter an offline alarm in the car GPS positioner?realtime tracking device
Last article:GPS radar detector
Next article:High precision timing system based on GPSD
Related Information
Dog gps tracker manufacturer
2023-04-23vehicle gps tracker webfleet solutions
2023-03-16Dog gps tracker custom
2023-04-11cat gps tracker sales
2023-04-11Gps speed limiter price
2023-04-23fleet gps tracking Processing
2023-04-23GPS Tracker Solution
2023-04-11fleet gps tracking Vendor
2023-04-23mini gps tracker sales
2023-04-23Car gps tracking Production
2023-04-23G06L
2022-06-21TK100N- Multi functional GPS Tracker
2023-10-06GF30 Magnet GPS tracker with Voice listen
2022-06-21TK103B
2022-06-20G200(L) -Magnet GPS Tracker
2022-06-20Centimeter -level high -precision 4G full Netcom GPS positioner.fleet management software webfleet s
2023-03-08Features of GPS navigation map
2022-12-14Where is the car GPS positioner?
2023-02-22The reasons and solutions for the slow reaction of the GPS screen.realtime gps tracker online Soluti
2023-05-06GPS system principle
2023-02-09How to use the car GPS positioner after installation?plug & play Obd gps tracker Processing
2023-03-28GPS navigation phone.portable gps tracker Solution
2023-06-07Advantages of traditional GPS and new technology GPS solutions
2022-10-15What are the components of GPS
2022-12-13Installation and Use Instructions for GPS Mobile Car Check.Hidden GPS Trackers manufacturer
2023-09-12The Application of GPS Navigation System in Road Engineering.4G GPS Tracker for vehicles equipment
2023-08-24mini gps tracker.Purchasing a used car requires testing and removing the GPS tracking device
2023-11-09GPS helps you avoid the electronic eye
2023-02-02Precautions for installation of Beidou 4G wiring GPS positioner.obd-II port gps tracker Manufacturin
2023-03-28GPS module NMEA0183 standard statement.portable gps tracker Factory
2023-07-12