We improved the antenna efficiency of the Taeduk Radio Astronomy Observatory (TRAO) 13.7-m radio telescope by adjusting the antenna panels based on digital photogrammetric measurements. First of all, we measured the surface accuracy of the main reflector of this antenna at three elevation angles of 35°, 45°, and 60°. We performed a total of four sets of the photogrammetric measurements and panel adjustments. When adjusting the panels, we positioned the antenna to the zenith and applied the measured data sets at the elevation of 45°. We found that the antenna surface accuracy has been improved by a factor of ~ 3 times after the final adjustment in comparison with the value before the adjustments. And we also found that the antenna surface accuracy tended to be slightly better at the elevation angles of 35° and 60° than that at the elevation angle of 45°. After the final panel adjustment, the aperture and beam efficiencies of the telescope have has been improved from 35% to 44%, and from 41% to 51%, respectively.

ABSTRACT
1. 서론
2. 안테나 경면 측정 및 조정
    2.1. 사진측량법 측정 준비
    2.2. 사진 촬영 및 경면조정
    2.3. 효율측정
3. 결론 및 토의
REFERENCES

• 이창훈(한국천문연구원) | CHANGHOON LEE (Korea Astronomy and Space Science Institute)
• 정재훈(한국천문연구원) | J. H. JUNG (Korea Astronomy and Space Science Institute)
• 강현우(한국천문연구원) | H. W. KANG (Korea Astronomy and Space Science Institute)
• 김현구(한국천문연구원) | H. G. KIM (Korea Astronomy and Space Science Institute)
• 이영웅(한국천문연구원) | YOUNGUNG LEE (Korea Astronomy and Space Science Institute)
• 정진오(하이게인 안테나(주)) | J. O. JUNG (High Gain Antenna Co., Ltd.)
• 손영득(하이게인 안테나(주)) | Y. D. SOHN (High Gain Antenna Co., Ltd.)
• 배민수(하이게인 안테나(주)) | M. S. BAE (High Gain Antenna Co., Ltd.)