source:truck tracking webfleet solutions release time:2022-11-07 Hits: Popular:realtime gps tracker online
The Global Positioning System (GPS) is a space based radio navigation system originally developed by the US Air Force. Although GPS was originally developed for use as a military positioning system, it also has an important impact on civil society. In fact, you can now use GPS receivers in vehicles, ships, and even mobile phones. The GPS navigation system consists of 24 groups of satellites, all of which transmit multiple signals in L1 and L2 bands. Through 1.57542 GHz L1 frequency band, each group of satellites generates 1.023 Mchips BPSK (binary phase shift) spread spectrum signal. Spread spectrum sequences use virtual random number (PN) sequences called C/A (coarse acquisition) codes. Although the spread spectrum sequence is 1.023 Mchips, the actual signal data transmission rate is 50 Hz [1]. In the original deployment of the system, the accuracy error of the GPS receiver can reach more than 20~30 meters. This error is caused by the random frequency error added by the US military for security reasons. However, this error signal source, called Selective Availability, was canceled on May 2, 2000. Today, the maximum error of the receiver does not exceed 5 meters, while the general error has been reduced to 1~2 meters.
Whether in L1 or L2 (1.2276 GHz) bands, GPS satellites will generate so-called "P code" auxiliary signals. This signal is a modulated signal of 10.23 Mbps BPSK, and also uses PN sequence as spread spectrum code. The military carries out more accurate positioning operations through the transmission of P code. In the L1 band, the P code is transmitted 90 degrees out of phase through the C/A code to ensure that the two kinds of signal numbers can be measured on the same carrier [2]. P code can reach - 163 dBW signal power in L1 band; Up to - 166 dBW in L2 band. Relatively speaking, if the C/A code on the earth surface is used, the minimum broadcast power of - 160 dBW can be achieved in the L1 band.
Read recommendations:
gps vehicle tracker Processing
3000mAh Magnet Asset GPS Tracker
International requirements aircraft must be equipped with GPS
Last article:Vehicle Management System Based on Differential GPS Technology
Next article:Five requirements that a good GPS module must meet
Related Information
simple gps tracking Factory
2023-04-23fleet gps trackers
2023-04-23OBD GPS Tracker distributors
2023-04-23portable gps tracker Vendor
2023-04-23simple gps tracking
2023-04-11gps vehicle tracker Vendor
2023-04-23real-time gps tracking Factory
2023-04-234G GPS Tracker Processing
2023-04-23Car gps tracking price
2023-04-11fleet tracking mobile app
2023-03-163 Years Disposable Asset GPS Tracker
2025-03-31G200NY -Cow/Camel GPS Tracker
2022-06-21NB20 -4G Bluetooth Smart Pet Tracker
2022-06-21C32Plus (9~90V E-bikes/Motorcycle/Car gps tracker)
2022-06-21G500L -4G OBD GPS Tracker
2022-09-06GPS power consumption and noise
2022-09-01Main Errors in GPS Positioning and Their Elimination Algorithm
2022-12-10GPS_GPRS system composition and characteristics
2022-10-28Anti-kidnapping smart bracelet comes out with built-in GPS system
2022-08-10GPS early warning
2022-07-27GPS ground control part.pet gps tracker cat supplier
2023-07-13How to use the Beidou GPS positioner.plug & play Obd gps tracker Processing
2023-04-14What are the key points for purchasing in car GPS.personal gps tracker Solution
2023-06-16Differences between GPS cold start and hot start
2022-12-30The Application of GPS in Military Affairs.gps tracker with magnet distributors
2023-09-09High precision timing system based on GPSD
2022-11-18GPS module with AGPS function
2022-10-12GPS tracking purchase method.4G GPS Tracker for vehicles Manufacturing
2023-08-17System Composition of GPS PPS Clock Synchronization Technology
2022-11-11Recommended Minimum Specific GPS/TRANSIT Data (RMC) GPS recommended positioning information
2022-09-28