We present the beam pattern measurement of the Tianlai Cylinder Pathfinder Array. As it is a pure drift-scan instrument, we exploit the North-South motion of the Sun to demonstrate that the primary beam is factorizable. Leveraging this property, we decompose the primary beam into independent East-West (E-W) and North-South (N-S) components. Using the Sun as a calibration source, we obtain the E-W beam profiles at various elevations, applying normalization to eliminate the effects of solar activity. Subsequently, we simulate the observed signals using a sky map model to derive the best-fit N-S beam. The results of this work are consistent with previous expectations.
Cite
@article{arxiv.2604.20262,
title = {Measuring Tianlai's primary beam using sky model},
author = {Yunbo Geng and Furen Deng and Jixia Li and Shifan Zuo and Shijie Sun and Yichao Li and Fengquan Wu and Yougang Wang and Xuelei Chen},
journal= {arXiv preprint arXiv:2604.20262},
year = {2026}
}
Comments
15 pages, 11 figures, Accepted by Research in Astronomy and Astrophysics