Argus is the Latinized form of the Ancient Greek word Argos, which was the name of Argus/Argos Panoptes ("All-Eyes"), a giant with a hundred eyes from Greek mythology.
DARPA probably figured the reference fit well with a flying drone capable of seeing and tagging targets from a distance of 20,000 Feet (6100 Meters) in the air.
Indeed, the Defense Advanced Research Projects Agency has introduced the Autonomous Real-Time Ground Ubiquitous Surveillance Imaging System, or ARGUS for short.
It is said to be the most advanced aerial surveillance system, with a price to match: $18.5 million for the whole program (13.78 million Euro).
The 18.5 gigapixel camera has 368 sensors and is good enough to see what color the clothes of pedestrians are, even from that height.
As for processing power, around 1 million terabytes of video can be streamed from it each day, or 5000 hours of HD footage.
No word on whether or not ARGUS is deployed at the moment.