| 其他摘要 | Near-Earth asteroids are products of the early formation of the solar system. The high-precision position measurement data of Near-Earth asteroid is of fundamental great significance to the scientific research on the origin and evolution of the solar system. High-precision position measurement data also play an important role in studying the dynamics of small celestial bodies in the solar system and revealing some non-gravity effects. It also has its unique advantages in establishing a stable dynamic reference frame and plays a fundamental role in deep space exploration. In addition, the high-precision positioning of Near-Earth asteroids, especially those with potential threats to human beings, is of great significance to protect the living environment of human beings and to make early warning and disaster prevention measures for potential threats in advance.GEO satellite has great application value in national economy and people’s livelihood due to its unique static ground characteristics. High-precision optical positioning observation on the ground can restrict the angle of the satellite, improve the satellite orbit, reduce the threat of satellite collision and other aspects.In this paper, based on the CCD astrometric theory and image processing theory, CCD astrometric observation of Near-Earth asteroids are studied, error measurement and correction of multi-function astronomical theodolite are studied, and experimental research on GEO satellites astrometric observations were conducted. The main work of this paper includes the following 4 parts: 1、In solving the problem of star matching, a matching method based on star pair rotation angle statistics is proposed, which reduces the computational complex-ity compared with the trigonometric matching method.Experimental results show that this method is robust and efficient. 2、In 2018, we made some high-precision position measurements of 2017 VR12, Midas and Camillo by the 1m telescope of Yunnan astronomical observatories, among these, 2017 VR12 and Midas are potentially hazardous asteroids(PHA).We applied the latest high precision Gaia DR2 star catalog as the reference star catalog and compared the accuracy of the asteroid ephemeris from JPL with that from IMCCE.Due to the fact that the target 2017 VR12 was close to the earth during the observation period, the apparent velocity was fast. The influence of PSF method and barycenter method on the accuracy of centroid centering results of the elongated stars was compared, and the results showed that the barycenter method had a smaller dispersion .The mean (O-C)s of 2017 VR12 in right ascension and declivity were -0.′′124 and -0.′′655, and the dispersions were 0.′′ 112 and 0.′′273.The average (O-C)s of the target Midas in right ascension and declination were -0.′′023 and -0.′′047, and the dispersions were 0.′′081 and 0.′′058.The average (O-C)s of the target Camillo in right ascension and declination were -0.′′014 and 0.′′048, and the dispersions were 0.′′035 and 0.′′051.There may be three reasons for the large deviation between observations and the ephemeris for 2017 VR12: Firstly, the centering errors caused by degraded CCD images; Secondly, the timimg system is poor, may cause a large bias; Thirdly, the accuracy of ephemeris may be poor due to the fact that the asteroid is near the earth. Fourthly, the accuracy of ephemeris may be poor due to lack of sufficient observational data. 3、Error measurements and corrections of multi-function astronomical theodolite.The multi-function astronomical theodolite instrument and its potential application values are introduced. The influence of instrument errors such as horizontal error, azimuth error, collimation error and optical axis pointing change on multi-azimuth observation is analyzed. At the same time, how to determine the local instantaneous astronomical longitude and latitude and azimuth difference, to establish the local reference frame is also analyzed. The vector method of multi-function astronomical theodolite is realized. 4、We used the multi-function astronomical theodolite to carry on the astrometric observation experiment of GEO satellite. Observations were planned and implemented, and data and images were processed. |
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