Determination of Zero Point for the Celestial Reference Frame(Ⅱ)-The Length of Arc Section Observed for Asteroids

It is very important for determination of the zero point of the fundamental reference frame to observe evenly the asteroid positions at all orbits, and it is also useful for the study of other subjects related. In this paper, we have calculated and analysed the magnitude range and distribution of the arc section for the asteroids in all orbit based on the observational ability of the Low Latitude Merdian Circle, and given the formula to calculate the length of the arc section observed for asteroids.