Determination of the Positions for the outer Planets with a High Precision Feasibil ity and Test

For a long time, the posit ional determination of the major planets is always one of the most important research field in Ast romet ry.How to determine precisely the positions of the planets at present time is the important purpose in this dissertation.Because the precise positional measurement of theinner planets is currently made by means of some new techniques, such as VLBI, radar ranging, satelli te observations and soon, it is interesting that the precise positions of some outer planets(Saturn, Uranus and Neptune)are measured by optical CCD observations.A new approach is presented in this paper.According to this approach it is required that the CCD observations are carried out by using a long-focus telescope, which is used to observe some satellites of an outer planet, and a meridian circle, which is used to observe some faint stars when working in a CCD drift scanning manner.Furthermore, the observations obtained with No.1 CCD and 1024 ×1024 PI CCD on 1m telescope at the Yunnan Observatory are used to determine the position of some faint stars related to the positions in the ephemeris of Uranian satellites.The results show that the positional precision for each star is comparable to or better than the best observations of U ranian satellites that is used to improve their ephemeris.Besides, the computat ional method of the positions for the Uranus and its satellites is an important part of this dissertation.Finally, the feasibility to determine precisely the positions of these outer planets(Saturn, Uranus and Neptune)in China is analyzed.