木星土星边缘的椭圆拟合  

Least-square Fit to the Edge of Jupiter and Saturn for its Precise Position

作　　者：彭青玉[1] 

机构地区：[1]暨南大学计算机科学系

出　　处：《云南天文台台刊》2003年第4期43-48,共6页Publications of the Yunnan Observatoty

基　　金：国家自然科学基金资助项目(10273015).

摘　　要：将CCD观测的木星或土星光环图像二值化,再用"四邻点模板"检测获得二值图像的边缘,最后用椭圆方程迭代拟合边缘,可以获得行星几何中心的位置。这被证明是一种高精度的位置测量方法[1,2]。本文给出了用椭圆拟合检测边缘的全部公式及有关说明。Astrometric observations of major planets and their satellites are very important.These observations can be directly used for the improvement of the orbit theories of planets and their satellites,and also for the space exploration in our solar system.At present,some new techniques (such as radar ranging and interferometer) are available to observe the inner planets (Mercury,Venus and Mars) with high precision.Unfortunately,due to the principle limitations of these new techniques,the outer planets can be almost observed only using traditional optical methods,such as meridian circles.Since their 'phase effects' on positional measurement,their positional accuracies,usually ±0.″20～0.″50 are poor.Recent observations adopt mainly an indirectly method,i.e. first observing a satellite of a planet and then deriving the planet's position by using the satellite's ephemeris.The accuracy of this method is usually in the range of ±0.″10～0.″20. It must be paid attention to the flaw of this method,i.e. with an assumption that the orbit theory of the satellite is precise enough.Obviously,the observed planet's position will be subject to the theoretical error of the satellite.Recently,Peng et al. have found a new method based on the edgedetection of Jupiter and obtained very good results with a standard deviation as small as ±0.″03. A similar method has already applied to Saturn and its satellites.The results show that the geometric center of Saturnian ring has good precision better than ±0.″05. In this paper,all used formulae of the image processing and related notions are given.We expect it,together with the papers to be useful if some researchers are interested in this new method.

关 键 词：木星 土星 椭圆拟合 图像处理 行星位置 位置测量 CCD观测 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]