<title>Instrumentation of LOTIS--Livermore Optical Transient Imaging System: a fully automated wide-field-of-view telescope system searching for simultaneous optical counterparts of gamma-ray bursts</title>

LOTIS is a rapidly slewing wide-field-of-viewtelescope which was designed and constructed to search for simultaneous gamma- ray burst (GRB) optical counterparts. This experiment requires a rapidly slewing (less than 10 sec), wide-field-of-view (greater than 15 degrees celsius), automatic and dedicated telescope. LOTIS utilizes commercial tele-photo lenses and custom 2048 X 2048 CCD cameras to view a 17.6 X 17.6 degree field of view. It can point to any part of the sky within 5 sec and is fully automated. It is connected via Internet socket to the GRB coordinate distribution network which analyzes telemetry from the satellite and delivers GRB coordinate information in real-time. LOTIS started routine operation in Oct. 1996. In the idle time between GRB triggers, LOTIS systematically surveys the entire available sky every night for new optical transients. This paper will describe the system design and performance.