Passive Electromagnetic Sensor Arrays (Passive EMs or PESAs) have an unfortunate name. The human eye could be characterized as a passive EM detector. With regard to space craft the PESAs are devices able to measure the frequency, amplitude and directionality of EM waves. Sophisticated PESAs can parse the cacophony of EM waves found in deep space by employing polarizing filters and selective detectors. Because EM waves can be blocked or distorted by the ship's hull or disrupted by internal EM sources the effectiveness of PESAs is dependent on the geometry of their design and installation. Most ships employing PESAs have a blind spot.

Login or Register to Award axlerowes XP if you enjoyed the submission!
? axlerowes's Awards and Badges
Longest Comment 2010 Dungeons of the Year 2010 Most Comments 2012