Scientists from A*Star develop new satellite tech

Antenna arrays allow satellites to transmit data to earth with fewer interruptions

Local scientists have developed new technology that will allow satellites to transmit data to earth more quickly, efficiently and with fewer interruptions.

Satellite communication is used in every part of the modern man's daily routine, from checking weather forecasts to streaming videos on Netflix to texting friends and family.

The new technology - developed by a team of scientists from the Agency for Science, Technology and Research (A*Star) - addresses an existing flaw where satellites closer to earth, known as Low Earth Orbiting (LEO) satellites, have their data streams interrupted intermittently during orbit.

Today, for information to be transmitted to satellite stations on earth, LEO satellites must bounce data to a geostationary satellite, or GEO satellite. A GEO satellite is an earth-orbiting satellite situated at a much higher altitude of about 35,800km above earth.

LEO satellites have to physically rotate to maintain a constant, uninterrupted line of contact to GEO satellites. Without this constant line of sight, the connection is broken, and no information gets sent to earth via the GEO satellite.

In an interview with The Straits Times last week, the A*Star team shared how they have devised antenna arrays that can be installed onto LEO satellites.

Like feelers on a bee that detect airborne scents miles away, the antenna - with the help of a new algorithm coded into it - transmits the satellite signal in the required direction, without the satellite itself having to rotate at all. This will allow for a constant data link, with information being continually transmitted from a LEO satellite to a GEO satellite, and then to earth.

Apart from reducing disruption in communications, having an antenna that pinpoints a correct direction might reduce the wear and tear to satellites, as the machine does not need to turn and adjust itself, said Dr Peng Xiaoming, head of the satellite department and senior scientist at A*Star's Institute for Infocomm Research.

"This technology allows a LEO satellite, when moving, to transmit data anywhere, any time, making for better and more accurate earth observation. So this is a new way to communicate data back to the earth from satellites, in a real-time, immediate way," he said.

A*Star said the technology is patented, and its scientists have conducted extensive trials on a prototype.

The agency plans to work with the National University of Singapore to install these antenna arrays onto newly designed LEO satellites in future.

Dr Peng's team is also working on another satellite project co-funded by the Maritime and Port Authority of Singapore, to develop a real-time tracking system for ships. The goal is for the system to be able to pinpoint the exact location of all ships in its database at any one time, akin to tracking a package's movements.

This new satellite technology will allow data to be transmitted from ship to ship, and from ships to shore control centres, Dr Peng said, noting that only one-way reporting is available now for maritime communication: from ships to shore control centres, but not the other way round.

The new technology is meant to allow shore stations to broadcast unusual weather patterns, areas to avoid and other information to ships. It "will increase the bandwidth for maritime communication, and will allow for the routes of ships to be coordinated amid a high volume of maritime traffic", Dr Peng said.

He and his team of 20 scientists have been working on these projects since 2014.

A*Star estimates these two forms of technology could be incorporated into new satellites by 2023.

A version of this article appeared in the print edition of The Straits Times on April 16, 2019, with the headline 'Scientists from A*Star develop new satellite tech'. Print Edition | Subscribe