After more than seven years, the news of Malaysia Airlines MH370 is once again on the hot search. In a report released on November 30, British aeronautical engineer Richard Godfrey said he used revolutionary tracking technology to find the Malaysia Airlines MH370 airliner. He said the plane crashed in the Indian Ocean 1,993 kilometers west of Perth and is now located 4,000 meters below sea level.
The news also gave everyone renewed hope of finding the flight. In this regard, experts from the team of the Flight Global Tracking and Surveillance Technology Research Center of the Civil Aviation University of China said that the method used by the British aviation engineer to find MH370 has a certain degree of credibility in theory, but requires a lot of data support and analysis, whether it can accurately find the location of MH370 aircraft, it is necessary for him to further disclose the data and detailed process of analysis.
What technology did British aviation engineers use to find MH370?
According to experts from the center team, British aeronautical engineer Godfrey used the data collected by the “Weak Signal Propagation Reporter” (WSPR) and software built around the world to estimate the location of the MH370 aircraft.
WSPR is a software that allows radio enthusiasts to join a global network of low-powered propagation beacons, developed by Nobel Prize-winning physicist Joe Taylor of Princeton University.
The software allows you to use your own radio to transmit beacon signals and also to receive beacons from other stations with similar equipment in the same amateur band. Each participating station receives the beacons while uploading them to a Web server, and after the signal is transmitted, the location and strength of the reception can be found on a map, which can even show the path of the signal.
“The globally established ‘Weak Signal Propagation Report’ (WSPR) mechanism is equivalent to laying crisscrossing beacon lines over the Earth, and when an aircraft crosses certain beacon lines, it causes weak interference to that beacon signal.” The center team experts introduced that if we can obtain the beacon signals worldwide, connect all the interference information (accurate sending and receiving time and location) in series according to the time point, and then exclude the interference not caused by MH370 aircraft, the remaining interference information should be caused by MH370 aircraft.
In the time period when MH370 was last lost, there were almost no other planes in this direction in the South Indian Ocean. Therefore, in this range, to find the connected beacon signal and the weak signal propagation of the transceiver location point, you can initially determine the MH370 aircraft through the location point.
Richard Godfrey claimed to have found 7 transceiver points disturbed by MH370, so if these 7 transceiver nodes are connected, combined with the earliest approximate range determined by maritime satellites, drift analysis and Boeing’s performance data, it will be able to predict the last missing point of MH370 more accurately.
What are the current common aviation tracking and analysis technologies?
When MH370 was tracked, techniques such as ATC radar, military radar, Doppler effect (from Inmarsat’s satellite communication data), warning messages (from ACARS messages sent down from the aircraft), underwater beacons, buoy sonar, underwater listening networks/hydrophones, towed sonar, and simulation through flight performance data were used, but all ended in failure.
Now more than seven years have passed, what advances have been made in commonly used aviation tracking and analysis technologies, and can they help rescuers quickly find the whereabouts of the aircraft when they encounter similar situations again?
Center team experts said that the current common aviation tracking and analysis technology is divided into three main categories.
The first category is based on the ground data communication network tracking services, is the ground data communication service providers to integrate a variety of surveillance data to provide flight tracking services.
These tracking services integrate various location data sources operated by ground data communication service providers, mainly aircraft communication addressing and reporting system, contractual automatic correlation surveillance, broadcast automatic correlation surveillance, radar surveillance data, high-frequency data chain, etc.
This type of tracking is based on existing technology, which can fully apply the fusion of data resources held by ground communication service providers to achieve location acquisition at a lower cost, but is limited due to the coverage of ground stations.
The second type is the tracking service based on a satellite communication system, which is a satellite communication service provider using the satellite communication capability to provide flight tracking service.
For example, the satellite-based ADS-B operated by Canada’s Aireon makes full use of existing airborne equipment to achieve blind global coverage by receivers, and will be deployed in 2019 to achieve 4D position acquisition with an update rate as low as 8 seconds, and there are plans to build a satellite-based ADS-B constellation in China.
The short message communication function of China’s Beidou system can be used for aircraft position acquisition and global tracking, which is the only independent and controllable tracking technology in China, but it requires a series of work such as airborne equipment airworthiness certification.
The third type of tracking service is based on airborne flight data acquisition equipment, which is developed by airborne equipment manufacturers to acquire flight status data and provide tracking service by renting satellite communication links to transmit down to the ground.
Spacecraft need to be retrofitted with new airborne equipment, and using airborne equipment to acquire flight data and use satellite communications to downlink the data is a more flexible way to achieve global coverage. However, it is more costly because it involves modification of airborne equipment and airworthiness certification. Source