The Peritarch Targeter was a suite of highly advanced tracking technologies employed by the Fulmentarus Terminators of the Ultramarines Legion during the Great Crusade and Horus Heresy eras of the late 30th and early 31st Millennia.
A sophisticated weapons tracking Augury system which uses the sum of the different scanning arcs of the Augur units carried by the full squad of Terminators to augment its abilities, the Peritarch Targeter is capable of piercing the densest obstructions and securing near-impossible firing solutions.
This allowed the Fulmentarus to unleash volleys from the Cyclone Missile Launchers with near pin-point accuracy.
- The Horus Heresy - Book Five: Tempest (Forge World Series) by Alan Bligh, pg. 235