truck tracking webfleet solutions

Home > NEWS > Other information > truck tracking webfleet solutions

Company News

Industry News

GPS Global Positioning System

source:truck tracking webfleet solutions release time:2022-08-12 Hits:     Popular:realtime gps tracker online

  

  Due to the limitations of the Meridian satellite system, in 1973 the United States began to plan to develop a new navigation and positioning system, the GPS positioning system. After 20 years of hard work, the system was initially built and put into use in 1993. At this time, the system has a total of It consists of 24 satellites, including Block I experimental satellites and Block II, Block IIA working satellites. After the completion of the GPS navigation constellation, the use of C/A codes for navigation and positioning can also achieve high positioning accuracy. Therefore, considering the huge use of GPS in the military field, in order to prevent the enemy from using GPS to endanger the national security of the United States, the United States defense The Ministry stipulates that the SA technology should be implemented on all working satellites, that is, it is considered to reduce the accuracy of the navigation system. There are two specific technical means:

  1. A technology that artificially adds errors to the broadcast ephemeris of the satellite to reduce the accuracy of the satellite ephemeris.

  2. Technology, consciously adding a pseudo-random process rapid change to the satellite clock frequency.

  On the other hand, in order to prevent the enemy from electronically spoofing and electronically jamming GPS satellite signals, the US Department of Defense has implemented the AS policy. The specific method is to add a strictly confidential W code to the GPS P code. After modulo two addition, a completely secret Y code is generated. Although the AS policy is a defensive measure, it also limits the possibility of unlicensed users to use the Y code, so it is impossible to obtain high-precision ranging codes, which greatly reduces the navigation accuracy.

  Later, the GLONASS satellite navigation system managed by Russia announced that it would not implement the SA policy, so the positioning accuracy of its navigation system was much higher than that of the GPS system using the SA policy. Announced in 2009 to suspend the implementation of SA.

  As satellite navigation systems play an increasingly important role in various fields of military and civilian use. However, the original GPS system has many shortcomings, such as: 1. It is difficult to receive satellite signals in hidden areas; 2. The energy of C/A code and P code is concentrated near the center frequency and is prone to human interference; 3. L2 carrier Ranging code is not modulated on the device, which makes it impossible for ordinary users to perform dual-frequency ionospheric delay correction, which affects positioning accuracy. Therefore, the C/A code was modulated on the L2 carrier of the navigation satellites of the subsequent Block IIR-M and Block IIF models, and later changed to the L2C code, so that civilian users can also use dual-frequency observation to improve positioning accuracy. Later, the L5 signal was added to the GPS navigation satellite after Block IIF, so that tri-frequency positioning can be used for non-military users.


Read recommendations:

gps tracker for kids supplier

Cantrack G05

YG119- Hunting Dog GPS tracker

GPS installation step

Issues that need attention during the purchase of GPS vehicle terminals.plug & play Obd gps trac

Last article:GPS positioning technology

Next article:Composition of GPS system

Related Information

gps vehicle tracker wholesale

2023-04-23

vehicle gps tracker wholesale

2023-04-23

Cantrack TK100

2023-03-16

gps tracker für auto webfleet solutions

2023-04-11

GPS Tracker for vehicles Manufacturing

2023-03-16

Gps speed limiter wholesaler

2023-04-23

car gps tracker Factory

2023-04-23

trailer gps tracker

2023-03-16

fleet gps trackers Solution

2023-04-23

gps vehicle tracker manufacture

2023-04-11

GF20-Mini Magnet GPS Tracker

2022-06-21

G500L -4G OBD GPS Tracker

2022-09-06

TK100N- Multi functional GPS Tracker

2023-10-06

GF30 Magnet GPS tracker with Voice listen

2022-06-21

G06L- 4G Car GPS Tracker

2022-09-06

How to judge the impact of GPS positioner on battery life.real-time gps tracking Manufacturing

2023-04-06

GPS system architecture and analysis

2022-09-01

Overview of the car navigation system.Magnetic gps tracker Manufacturing

2023-05-18

GPS angle calculation method

2022-08-16

GPS's current application scale and level

2023-02-16

GPS application field

2022-12-29

Introduction to GPS

2022-09-28

GPS RTK principle.gps tracker for kids company

2023-07-03

How to realize the function of GPS monitoring system?

2022-12-02

What are the differences between car navigation and mobile phone navigation?gps tracker with magnet

2023-04-11

The introduction of GPS in the field of logistics.gps tracker no monthly fee Production

2023-05-06

The Development History of GPS in the United States.4G GPS Tracker for vehicles manufacture

2023-08-19

GPS receiver work principle.gps tracker no monthly fee Manufacturing

2023-04-23

GPS elevation application.pet gps tracker cat company

2023-07-21

Precautions before installing GPS intelligent positioning terminal.car gps tracker manufacturer

2023-09-15