How did Xu Guangqi make the new calendar more scientific?

Xu Guangqi knew the importance of astronomical observation. In order to make the new calendar more scientific, Xu Guangqi organized the staff of the Calendar Bureau to observe solar eclipses, five-star movements and solar terms many times during the calendar revision process, and obtained a lot of scientific data. Whenever there is an eclipse of the sun and the moon, he often goes to watch the weather in person and tries his best to master the first-hand information about the time and food. Previously, the observation of solar and lunar eclipses in China was mostly naked eye observation, and the accuracy was very low. Especially when observing the eclipse, it is difficult to determine the time of the first loss and the last contact, and it is also difficult to determine the size of the eclipse, and it is even more difficult to find the snacks of the eclipse. In ancient times, the basin image method was also used to measure solar eclipse, but it was often disturbed by water surface fluctuation. Xu Guangqi has made astronomical observation with telescope technology just imported from China, and achieved good results.