What is the function of vehicle GPS positioning system?

The functions of vehicle-mounted GPS positioning system: accurate positioning, electronic fence, camouflage, historical reproduction and street view. Global positioning system.

GPS global positioning system adopts multi-satellite high-orbit ranging system, with distance as the basic observation value. By measuring the pseudoranges of four satellites at the same time, the position of the receiver can be calculated. Because ranging can be completed in a very short time, that is, positioning can be completed in a very short time, it can be used for dynamic users.

Modern ranging is essentially to calculate the distance by measuring the propagation time of radio signals. The round-trip propagation delay can be measured, and the unidirectional propagation delay can also be measured. Round-trip propagation ranging is active ranging, which requires both satellites and users to have the ability to send and receive. For users, this not only greatly increases the complexity of the instrument, but also is very unfavorable from the perspective of concealment, because the transmitted signal is easy to be exposed. One-way ranging (passive ranging) largely avoids the above shortcomings.

Extended data:

A GPS receiver is mainly composed of a GPS receiving antenna, a GPS receiver host and a power supply.

1.GPS receiver antenna

The antenna of GPS receiver consists of antenna unit and preamplifier. The function of antenna is to convert the weak electromagnetic wave energy of GPS satellite signal into corresponding current, and amplify the received GPS signal through preamplifier.

2.GPS receiver host

The receiving host consists of frequency converter, signal channel, microprocessor, memory and display. The main task of the frequency converter is to convert the received L-band RF signal into a low-frequency signal. Channel is the combination of software and hardware, and it is the core part of the receiver. Its function is to search, tow and track satellites, despread and demodulate broadcast message signals into broadcast messages, and carry out pseudorange measurement, carrier phase measurement and Doppler frequency shift measurement.

3.GPS receiver power supply

There are two kinds of power supply for GPS receiver. One is internal power supply, generally using lithium batteries, mainly to supply power to RAM memory. The other is an external power supply, usually rechargeable 12V DC nickel-cadmium battery.