[Source] A spy ray was a sophisticated surveillance device developed by Doctor Nasan Godera for the Galactic Republic during the Great Galactic War with the Sith Empire. By projecting beams of particles that would pass through or reflect off of matter depending on the object's density, the spy ray was able to generate high-resolution images of targets across an entire star system, and it saw great use in the hands of the Strategic Information Service, the Republic's primary intelligence agency.