Alexander Rügamer, Dr Jan Wendel
The main purpose of SORUS is to store short sequences of PRS PRN (pseudo-random noise) code chips on user receivers prior to missions. These PRS PRN code chips enable a user receiver to calculate a Galileo PRS position at predefined points in time. All the advantages of PRS are maintained in the process, including its robustness against jamming and spoofing and the access it provides to a secure navigation solution for authorised users. At the same time, SORUS circumvents all the drawbacks of conventional PRS receivers and server-based techniques: No need for a PRS security module on the user receiver; no size, weight, or power (SWaP) problems; no keying issues; no handling of controlled items on the user side; no need for a communication link that would lead to the availability and radio silence issues; and no security issues thanks to the short PRS PRN code chip sequences, which are only valid for the limited duration and area of a given mission. SORUS enables PRS navigation for a wide range of users while considerably reducing security requirements and Galileo PRS costs per user device. Police, special forces, and other authorised Galileo PRS users could use this method to equip their UAVs with a secure, trustable, and unspoofable positioning solution.
«SORUS is an enabling and highly innovative concept for operating UAVs autonomously and securely, based on the Galileo PRS signal. We fly PRS – better safe and secure than sorry!”»
Policy Advisor, German Federal Ministry of Transport and Infrastructure (BMVI)