Real-time flight position of aircraft

It is estimated that two days ago, many people went to the flight tracking website FlightRadar24 or FlightAware to track the flight information of an old woman. Because there are many people online at the same time, the website has been in a "crowded" state for a long time, and some new users simply can't squeeze in. The website was once "paralyzed". In fact, there are also some apps in China that can provide flight information, such as "very accurate". I often use it to check the take-off and landing time, airport status, flight status, weather conditions and the position in the air after taking off. So, why can we find their relevant information on computers, mobile phones or tablets in real time when planes are flying in the air? In fact, flight data contains a lot of information, which is common. We usually pay more attention to the weather, flight information, airspace flow and so on. Generally speaking, there are three main sources to obtain these data: the first is to establish an information sharing mechanism with relevant domestic institutions. By establishing cooperative relations with domestic airlines, airports and aviation management agencies, the relevant data of airports, weather and specific flights are obtained. The second is to establish contact with relevant foreign institutions. Generally, it is difficult for domestic information recipients to directly cooperate with foreign airlines or airports. For the acquisition of foreign flight information, they usually establish contact with some foreign data service providers to obtain detailed data of foreign airports and flights. The third is to establish their own data acquisition facilities. For some powerful information companies, in addition to the above two ways, conditional information collection facilities will be built by themselves, actively collecting flight dynamic data, or will be built in cooperation with the airport. ADS-B equipment is the most widely used facility here. So, what is an ADS-B device? Before the ADS-B system was put into operation, pilots and controllers on the ground relied on ground radar and short-range radio navigation equipment to collect and track flight information. However, these ground technologies and systems do not take advantage of the high-precision performance of satellite monitoring systems, and they are high in construction cost, vulnerable to lightning strikes, greatly influenced by topography and weather, and low in long-distance transmission efficiency. Therefore, the scope, accuracy and adaptability of aerial monitoring are greatly lacking. In areas where it is impossible or difficult to build these ground facilities, such as deserts and oceans, it is difficult to be monitored if planes fly over the sky. Under such circumstances, ADS-B system came into being, which is called "automatic correlation monitoring-broadcasting", that is, broadcasting automatic correlation monitoring system. Compared with traditional radar monitoring, the system does not need manual operation and query, and can automatically obtain relevant parameters directly through relevant airborne equipment. Then broadcast the basic information such as the position, altitude, speed, heading and identification number of the aircraft to the ground station or other aircraft in real time. Through this information, the controller can monitor the running state of the real aircraft in real time and dynamically. Judging from the composition of ADS-B system, it is mainly composed of several ground stations, airborne stations and airborne equipment of aircraft. Viewed from the plane, it is the source of information acquisition and generation. For example, the position information can be obtained from the GPS equipment carried on the plane, the altitude information can be obtained from the barometric altimeter on the plane, and the flight speed information can be obtained from the measurement results of the total air pressure entering the pitot tube of the plane. With the information source, we have to have the "channel" of information transmission, that is, the way and carrier of information transmission, which is equivalent to the signals of mobile, Unicom or telecommunications used in our mobile phones now. After the basic flight information is obtained through the corresponding equipment of the aircraft, it is automatically transmitted through VDL Mode4 (VHF data link mode 4), UAT (universal radio data link), 1090ES( 1090MHz S mode extended message data link) and other widely used methods. Therefore, from the ground, the most important thing is to receive this information. After receiving the broadcast information in the air, the ground network or point-to-point ground station displays the information on the terminal through corresponding algorithms, thus providing monitoring, control and inquiry for ground managers and users. Of course, this information can also be connected to the air traffic control automation system for reference by relevant departments and personnel. In fact, ADS-B is a two-way system, and its information can be sent from the plane to the ground, so that the basic information of the flight can be sent back or sent from the ground to the plane. The information sent mainly includes air traffic conditions, flight information services and meteorological information. According to this information, the crew on the plane can know the flight route weather and airspace restriction information in time, and provide guarantee for flight safety. Compared with traditional positioning and tracking technologies such as radar, ADS-B system has the advantages of low construction cost, accurate positioning, high transmission efficiency, no limitation of terrain and weather conditions, and high air-to-air and air-to-air coordination efficiency. It provides an effective guarantee for improving flight efficiency, flight safety and flight freedom, and is more and more widely used in real-time monitoring of civil aircraft, general aircraft, unmanned aerial vehicles and scene vehicles. However, ADS-B system also has its shortcomings, that is, it relies too much on GPS navigation system. If the navigation system fails, the ADS-B system will become "rootless water" and cannot operate normally. In addition, the ADS-B system does not have the function of information verification. If the information automatically generated by airborne equipment is inaccurate, the information obtained by the receiving equipment of the ground station cannot be verified and identified in time. These problems need to be improved and perfected in the future technical research. /feed/279759 ee 3d 6d 55 FB 1 1 179 ef 59 a5 af 14022 a4 DD 90 . JPEG？ token = 62 CBE 790 138 b35b 1d 56043 c 68 f 0 feac 8