Daytime Star Trackers

Capable of supporting navigation systems by overcoming GPS constraints, daytime star trackers offer an alternative to satellite positioning systems, which can be jammed and spoofed.

Coupled with an inertial unit, the daytime star tracker provides, day or night, an attitude measurement to ensure precise, robust, reliable, and discreet onboard geolocation information, without emitting any signals.

Astradia, daytime star tracker

Astradia : For a reliable & robust navigation system

Specially designed to meet the needs of aeronautical platforms, Astradia is autonomous and independent of GNSS radionavigation signals. Its compact size, monolithic design, and ease of integration make it a versatile and efficient solution for a wide range of missions, from civilian to military applications.

With a pointing accuracy of a few arcseconds (equivalent to 1 meter over 70 km), it recalibrates the natural drift of inertial systems, offering a resilient alternative to conventional systems like GPS and Galileo, which are highly vulnerable to jamming and spoofing.

About daytime star trackers

In 2016, at the request of the French Military acquisitions agency (DGA), Sodern joined forces with the Safran group, a European leader in inertial references systems, to design daytime star trackers. The aim is to create a star tracker which operates in the Earth’s atmosphere even in daytime, and which can be used on board military vehicles (planes, drones, etc.) to determine a position with a high degree of accuracy, without depending on the information provided by satellites.

The solution designed by Sodern and Safran combines a star tracker with an inertial reference system which measures the plane’s movements in the finest detail. In particular, this system will be fitted to military aircraft whose satellite positioning systems are often scrambled by hostile forces in theatre. Our solution will enable French armed forces to increase their autonomy and provide them with operational superiority in crisis situations.

4 test flights were carried out on board a government plane at the end of 2020 by the French Defense Procurement Agency. A precise position was obtained throughout the test phase, thus confirming the viability of our system. Across the trajectories of each flight, several stars were detected and tracked closely by the demonstrator.

Sodern is now working to adapt its solution to various military aircrafts and systems at the request of the French Military acquisitions agency.