We have developed a seeing monitoring system and measured seeing variation of the Bohyunsan Optical Astronomy Observatory (BOAO) and the Sobaeksan Optical Astronomy Observatory (SOAO) using a small telescope system. Our seeing monitoring system is similar to the differential image motion monitor (DIMM) installed at the ESO. The ooly difference between the BOAO and the SOAO seeing monitoring system is a detector system, a video camera at the BOAO and ST-4 camera at the SOAO. We confirmed that the seeing monitoring system at the SOAO can measure average seeing size inspite of its simple detector system. From the BOAO seeing measurement, we found that the seeing size changes fast.
We expect that our seeing monitoring system could be used for real time seeing monitoring after some improvement, and the data to be obtained would be very useful when we build adaptive optic system in the future.

• 육인수(한국천문연구원) | IN-SOO YUK (Korea Astronomy Observatory))
• 경재만(한국천문연구원) | JAE-MANN KYEONG (Korea Astronomy Observatory))
• 천무영(한국천문연구원) | MOO-YOUNG CHUN (Korea Astronomy Observatory))
• 권순길(서울대학교 지구환경과학부 천문학) | KWON SUN-GIL (Astronomy Program, SEES, Seoul National University)