The continuous advancement of science and technology has made the GPS positioning system more and more popular. Today, Xuntuo Kesheng Xiaobian will explain the components of the GPS positioning system for everyone. Mainly divided into three parts.
1. Space part
First of all, we need to know that the space part of the GPS positioning system is composed of 24 satellites (21 working satellites, 3 spare satellites). It is located 20,200km above the ground, and is evenly distributed on 6 track surfaces (4 for each track surface), with a track inclination of 55°. The distribution of satellites makes it possible to observe more than 4 satellites anywhere in the world and at any time, and to store navigation information in the satellites. GPS satellites due to atmospheric conflicts and other problems, with the passage of time, the navigation accuracy will gradually decline.
2. Ground control system
The ground control system consists of a monitoring station (MonitorStation), a master control station (MasterMonitorStation), and a ground antenna (GroundAntenna). The master control station is located in Colorado Spring, Colorado, USA. The ground control station is responsible for collecting the information returned by the satellite, and calculating the satellite ephemeris, relative distance, atmospheric correction and other data.
3. User equipment part
The user equipment part is the GPS signal receiving terminal. Its main function is to capture the satellites to be tested selected according to a certain satellite cut-off angle, and to track the operation of these satellites. When the signal receiving terminal captures the tracking satellite signal, it can measure the pseudo interval and interval change rate from the receiving antenna to the satellite, and demodulate the satellite trajectory parameters and other data. Based on these data, the micro-processing computer in the receiving machine can perform positioning calculation according to the positioning calculation method, and calculate the latitude, longitude, altitude, speed, time and other information of the user's geographic location. The receiver hardware and in-machine software and the post-processing software package of GPS data constitute a complete GPS user equipment. The structure of the GPS receiver is divided into two parts: the antenna unit and the receiving unit. The receiving machine usually uses two kinds of DC power sources, inside and outside the machine. The purpose of setting the internal power supply is to replace the external power supply without suspending continuous observation. The battery is automatically charged when the external power supply is used. After shutdown, the internal battery powers the RAM memory to prevent data loss. Nowadays, various types of receivers are getting smaller and lighter in size and lighter in weight, which is convenient for outdoor observation and use. The second is the user receiver. There are two types of single frequency and dual frequency. However, due to the price factor, most of the users purchased are single frequency receivers.
