  The Rapid Telescopes for Optical Response (RAPTOR) experiment is a spatially
distributed system of autonomous robotic telescopes that is designed to monitor
the sky for optical transients. The core of the system is composed of two
telescope arrays, separated by 38 kilometers, that stereoscopically view the
same 1500 square-degree field with a wide-field imaging array and a central 4
square-degree field with a more sensitive narrow-field "fovea" imager. Coupled
to each telescope array is a real-time data analysis pipeline that is designed
to identify interesting transients on timescales of seconds and, when a
celestial transient is identified, to command the rapidly slewing robotic
mounts to point the narrow-field ``fovea'' imagers at the transient. The two
narrow-field telescopes then image the transient with higher spatial resolution
and at a faster cadence to gather light curve information. Each "fovea" camera
also images the transient through a different filter to provide color
information. This stereoscopic monitoring array is supplemented by a rapidly
slewing telescope with a low resolution spectrograph for follow-up observations
of transients and a sky patrol telescope that nightly monitors about 10,000
square-degrees for variations, with timescales of a day or longer, to a depth
about 100 times fainter. In addition to searching for fast transients, we will
use the data stream from RAPTOR as a real-time sentinel for recognizing
important variations in known sources. Altogether, the RAPTOR project aims to
construct a new type of system for discovery in optical astronomy--one that
explores the time domain by "mining the sky in real time".
