Title: Observation Scheduling Scheme for the Subaru Telescope AUTHOR LISTING Toshiyuki Sasaki, George Kosugi Subaru Telescope, National Astronomical Observatory of Japan, 650 North A'ohoku Place, Hilo, HI 96720, USA Tel: 808-934-5081 FAX:808-934-5099 e-mail: sasaki@subaru.naoj.org, george@subaru.naoj.org Jun A. Kawai, Toyoaki Kusumoto, Norikazu Koura, Fujitsu America Inc. 100 Pauahi Street #213, Hilo, HI 96720 kawai@fujitsu.com, kusumoto@fujitsu.com, koura@fujitsuu.com Laurence Kramer, Anthony P. Krueger, Glenn Miller Space Telescope Science Institute, 370 San Martin Drive, Baltimore, MD 21218 kramer@stsci.edu, krueger@stsci.edu, miller@stsci.edu Abstract Optimization of observation sequences is a function necessary to get high efficiency and reliability of observations. We are now implementing scheduling software into the Subaru Telescope Observation Software System. The scheduling engine, SPIKE, developed at STScI are used with some modification for the Subaru Telescope. Implemented functions to the SPIKE are mainly 1) optimization of internal and external calibration frames, such as standard stars and Bias, Dark, or Comparison lines, respectively, and 2) inserting setup times for auto-guiding and Shack-Hartmann sensor measurements into a schedule. An observation target list prepared by observers with some necessary information, such as a instrument name, exposure times, color bands etc., are converted to SPIKE Lisp codes. A SPIKE output is inversely converted to Subaru commands to be executed with the Observation Control system. In real-time mode during observatios, a target list and observation logs, from which some targets are identified as observed, are fed to SPIKE to do re-scheduling. As targets observed are locked on its schedule previously determined, we get a new schedule consistent with observations done. With help of frame check methods, astronomical frames are examined to have enough calibaration frares observed. If not and satisfaction conditions are violated, we need re-scheduling to have reliability of observations. We will present an overall structure of the scheduling procedure with some samples of Subaru commands of a target list and resultant schedules. KEY WORDS Observation Scheduling Realtime Scheduling Observation Control Software