Scientists are testing an alternative to the Global Positioning System (GPS), using cellular signals as an emergency backup in case an aircraft's GPS signal is jammed or interrupted.
The new system can pick up signals from cell towers from an altitude of 24,300m - Photo: Sandia National Laboratories
The project, conducted by researchers at Sandia National Laboratory and Ohio State University (USA), aims to create a safety net for airborne navigation systems.
According to LiveScience on November 26, the research team used receivers suspended in the air to detect radio waves from communication satellites and cell towers associated with the aircraft. They then used this information to provide navigation data to the pilot.
The research team attached antenna systems to weather balloons and launched them into the stratosphere (at an altitude of 6-50km above the ground) between satellites and cell towers to detect their individual signals.
In theory, this antenna system could function as an emergency beacon if the pilot loses GPS signal.
Although GPS is highly accurate, it is not without flaws. GPS signals can be deliberately jammed in and around combat zones. Hackers can also "spoof" GPS signals to send false information about location or flight direction to pilots.
Furthermore, GPS systems can malfunction or stop working altogether. People could be in danger if a commercial aircraft loses its GPS signal. Therefore, the team believes a backup system is essential.
Currently, the research team still has to manually determine which satellite is sending which signal based on available reference data. In the future, the team will create an algorithm that allows antenna systems to automatically identify satellites and use satellite and cell tower data to determine a person's location and speed in real time.
Previous tests of this technology were limited to altitudes of 1,500-2,000m. However, the research team's new project has taken the antenna system to an altitude of 24,300m. If the system can send back reliable navigation data from this altitude, it could provide practical benefits for air travel .
Although the system hovers at an altitude of 24,300m to receive better signals from both the communication satellite above and the cell tower on the ground, this is not a perfect method. Satellites focus radio waves down to Earth for optimal signal reception on the ground, so a strong signal is not always guaranteed at the weather balloon's altitude.
Therefore, the research team needs to improve the detection capabilities and speed to account for the possibility of this error occurring in the future.
Source: https://tuoitre.vn/phat-develop-new-system-that-can-replace-gps-20241126113215133.htm
