Thales UK's optronic mast: the sonar invisible periscope alternative

We wrote earlier this year about RemoteReality’s omni-directional periscope camera. Thales UK has developed a similarly impressive electro-optics system, which provides improved surface visibility while allowing the ship to remain hidden from sonar detection. The optronic masts, which will be powered by Wind River VxWorks' mission-critical real-time operating system, are the result of a ten year, multi-million pound program, and will be installed in the Royal Navy’s Astute-class submarines.

Traditional submarines are vulnerable to detection when the periscope is used – however, the optronic mast uses a non-hull breaching design, in which the Sensor Head Unit extends from the submarine fin and rapidly captures a 360 degree scan, sending the image to the console screens in the sub’s operation center. The image can be then be analyzed at the leisure of the commander, with a reduced risk of detection. The optronics masts also incorporate multi-function antenna arrays, which monitor the radar environment, provide command and situational awareness of other radar equipped platforms, and enable a submarine to take early evasive action.

The Wind River VxWorks mission-critical real-time operating system runs on Thales’ quad PowerPC AltiVec COTS boards and AdaCore GNAT Pro. It powers the stabilization system, a high-performance 3 axis to sub-pixel accuracies; video and thermal camera control; communication with the in-hull systems; and the mechanisms and motors in the SHU. The SHU is a pressure proof, electro-optical assembly that contains high-performance cameras, optics, environmental sensors and stabilization mechanisms. It is can function in temperatures ranging from -15 degrees Celsius to 60 degrees Celsius, and can withstand a nearby explosion.

The Mast Control Unit uses two processors to control the mast raising equipment, control the stabilization system, and communicate with the submarine’s tactical, data and combat systems. The stabilization system is designed to compensate for the movement of the sub and the water, providing a clear image for analysis.

In addition to being used in the Royal Navy, the optronic mast technology is also being used by the Japanese Maritime Self-Defense Force.