Introduction to Car radio navigator – Principle
GPS is composed of space satellite, ground monitoring and user reception. There are 24 satellites in space forming a distribution network, which are respectively distributed in six geosynchronous orbits 20000 km above the ground with an inclination of 55 °. There are four satellites in each orbit. GPS satellites circle the earth every 12 hours, so that any place on the earth can receive signals from 7 to 9 satellites at the same time. There are 1 master control station and 5 monitoring stations on the ground responsible for monitoring, telemetry, tracking and control of satellites. They are responsible for observing each satellite and providing observation data to the main control station. After receiving the data, the master control station calculates the exact position of each satellite at each time, and transmits it to the satellite through three injection stations. The satellite then transmits these data to the ground through radio waves to the user receiving equipment. Only after more than 20 years of research and experiments on the GPS system, which cost US $30 billion, did the 24 GPS satellite constellations with a world coverage rate of 98% be formally deployed in March 1994. Now the application of GPS system is not limited to the military field, but has developed into various fields such as automobile navigation, atmospheric observation, geographical survey, ocean rescue, manned spacecraft protection and detection.
Introduction to Car Radio – Composition
The operation of GPS navigator also requires a car navigation system. It is not enough to have a GPS system alone. It can only receive the data sent by GPS satellites and calculate the user’s three-dimensional position, direction, speed and time of movement. It has no path computing capability. If the GPS receiver in the user’s hands wants to realize the route navigation function, it also needs a complete set of car navigation system including hardware equipment, electronic map and navigation software. GPS navigator hardware includes chips, antennas, processors, memory, screens, buttons, speakers and other components. However, as far as the current situation is concerned, there is not much difference in the hardware of GPS car navigators in the market, and it is difficult to distinguish between good and bad software maps. At present, there are eight mapping companies in China engaged in the mapping and development of navigation map software, such as 4D Tuxin, Kailide, Daodaotong, Chengjitong…. After years of continuous development and improvement, they have been able to provide quite good navigation map software. To sum up, a complete GPS car navigator is composed of nine main parts: chip, antenna, processor, memory, display screen, speaker, buttons, expansion function slot, and map navigation software.
Post time: Oct-17-2022