truck tracking webfleet solutions

Home > NEWS > Other information > truck tracking webfleet solutions

Company News

Industry News

Civil GPS

source:truck tracking webfleet solutions release time:2022-12-28 Hits:     Popular:realtime gps tracker online

  G06L- 4G Car GPS Tracker

  Generally, L1 carrier of GPS system is used for civil GPS, and the frequency is 1575.42 MHz. Two different pseudo-random noise codes, C/A code and P code, are loaded on this carrier frequency in a phase modulation manner. C/A code is a distance measurement code for civil use. The code length is 1023 symbols, i.e. 1023 times of jumping from digital zero to digital 1. The 1023 symbols repeat 1000 times per second, i.e. 1.023MHz, or once every millionth of a second. P code is a military code with a very long code length and a code speed of 10.23MHz, that is, it jumps once every millionth of a second.

  The GPS receiver calculates the time from satellite to receiver by comparing the symbol jitter, and then converts it into distance. Obviously, the time accuracy of P code is 10 times higher, and the distance accuracy is 10 times higher. The time accuracy of modern signal processing technology to calculate the symbol jitter is one percent of the code width. The distance converted from one millionth of a second is 300 meters, and its one percent is 3 meters. The precision of P code is one tenth of this value, namely 0.3m. In other words, when calculating the actual distance between a satellite and the receiver, the theoretical accuracy of C/A code is 3 meters.

  The receiver "knows" the distance between itself and the satellite, and cannot calculate its position, because it does not know the position of the satellite when transmitting radio waves. Therefore, a 50Hz navigation message is also loaded on the satellite carrier. This navigation message includes: satellite track parameters, clock parameters, orbit correction parameters, correction value of atmospheric refraction of GPS signals, etc. GPS receiver calculates the position of a satellite in space at a certain time through these parameters, then determines the distance between itself and the satellite, and then calculates its actual position. The navigation message has a total length of 1500 bits, and each cycle is 30 seconds in the case of 50Hz transmission.

  It may be boring, but this is one of the countless "why" hidden behind each GPS technical parameter. When you compare the technical parameters of various models of GPS receivers in GARMIN and MAGELLAN, you will find that the cold start time of all models of GPS receivers (that is, GPS knows nothing about the satellite and its location) is about 45 seconds. It is not that the manufacturer is lazy to improve the GPS performance, but it has reached the technical limit: 30 seconds out of 45 seconds are used to receive navigation messages, and the remaining 15 seconds are used to calculate the receiver position.


Read recommendations:

cat gps tracker wholesaler

mini gps tracker custom

G900LM J16-4G Car GPS Tracker

China Beidou will provide positioning and alarm services to the world

GPS components

Last article:Actual demand and development trend of GPS market

Next article:Accuracy of GPS

Related Information

vehicle gps tracker webfleet solutions

2023-04-11

Asset GPS Tracker

2023-03-16

gps vehicle tracker distributors

2023-04-23

4G GPS Tracker for vehicles manufacturer

2023-04-23

Pet GPS Tracker Manufacturing

2023-03-16

simple gps tracking supplier

2023-04-23

4G GPS Tracker Factory

2023-04-23

real-time gps tracking manufacturer

2023-04-23

fleet gps tracking Processing

2023-04-23

Gps speed limiter distributors

2023-04-23

P02L Smart Walkie-Talkie Tracker

2025-09-19

G06L- 4G Car GPS Tracker

2022-09-06

TK100 (GT06) Vehicle Tracker

2022-06-20

3000mAh Magnet Asset GPS Tracker

2025-03-31

G200NY -Cow/Camel GPS Tracker

2022-06-21

Introduction to GPS system functions

2022-11-11

How GPS Works

2022-10-22

The GPS implementation plan has three phases

2022-10-13

GPS application in agriculture.realtime gps tracker online manufacture

2023-04-24

Introduction to GPS World

2022-10-25

The Development of China's GPS Navigation Market.gps tracker for trailer manufacturer

2023-08-25

mini gps tracker.Purchasing a used car requires testing and removing the GPS tracking device

2023-11-09

GPS is classified by the working principle of the receiver.obd2 gps tracker verizon sales

2023-06-05

mini gps tracker.Installation and usage methods for automotive GPS locators

2023-11-08

Frequently problem solving of GPS positioner.realtime gps tracker online distributors

2023-03-09

Advantages and disadvantages of wireless gps trackers

2022-09-16

GPS RTK principle.gps tracker for kids company

2023-07-03

GPSSIM card installation instructions.personal gps tracker Production

2023-08-02

GPS positioning function

2022-12-10

The concept and composition of the car positioning terminal.gps tracker no monthly fee wholesaler

2023-04-04