Researchers develop celestial navigation system as a GPS alternative for drones

A surge in GPS jamming attacks in drone warfare has inspired Australian researchers to develop a celestial navigation system that uses visual data from stars rather than relying on the global positioning system.

Remote sensing engineers from the University of South Australia have combined celestial navigation with vision-based technology to provide an alternative means of nighttime navigation in environments where GPS is unavailable or unreliable. Their research is described in a new paper published in Drones.

“The size and weight of a stabilised imaging system, and the lack of precision, tend to be at odds with the operational requirements of the aircraft,” the research states. “Nonetheless, celestial navigation is one of the few non-emissive modalities that enables global navigation over the ocean at night in Global Navigation Satellite System (GNSS) denied environments.”

The study demonstrates a “modular, low cost, lightweight strapdown celestial navigation solution that is utilized in conjunction with Ardupilot running on a Cube Orange to produce position estimates to within 4 km”. By performing an orbit through a full rotation of compass heading and averaging the position output, the researchers demonstrated that the biases present in a strapdown imaging system can be nullified to drastically improve the position estimate. 

An iterative method is presented as part of the research, which enables the geometric alignment of the camera with the Attitude and Heading Reference System in-flight without an external position input. The algorithm is tested using real flight data captured from a fixed wing aircraft. 

UniSA researcher Dr Samuel Teague says the celestial navigation system can be integrated into standard drones, offering a dependable backup with impressive accuracy. “This type of navigation is ideal for operations over oceans, or in warfare zones where GPS jamming is a risk. Apart from the defence sector, it could also be highly useful for environmental monitoring.” Dr Teague says that by relying on passive celestial navigation rather than radio frequency GNSS signals, drones are resistant to jamming. 

Senior researcher Professor Javaan Chahl, DST Joint Chair of Sensor Systems in UniSA’s STEM unit, says the technology could enhance the operational capabilities of uncrewed aerial systems (UAS) across many industries. “For instance, in environmental monitoring over remote locations or long-endurance surveillance missions where GPS might be unavailable or compromised, this technology offers a valuable new capability.”

The project is part of UniSA’s research and development programme into drone technologies for defence and civilian applications. It is supported by the Commonwealth Scholarships Program and the Australian Government Research Training Program.

In a video explaining the research, Dr Teague says the technology will soon be tested in a real environment.