Precise calibration of CCD images with a small field of view

Abstract

Abstract. A precise astrometric calibration method is presented for a CCD image with a small field of view. Its detailed computational formulae are given, and its feasibility and accuracy are tested by the observations of both the star and Phoebe, the 9th satellite of Saturn. This new method can also be applicable to other planetary satellites, asteroids and optical counterparts of extragalactic radio sources.

Re-determination of Phoebe's orbit

“…This emphasizes the efficiency of the iterative process we used for computing the numerical integration of Phoebe's orbit. Table 4 also clearly shows that the new orbit yields very low residuals for the new observations by Qiao and Tang and by Peng et al (2004). The mean error µ of these residuals are as low as a few tens of milliarcseconds (45 mas in right ascension and 90 mas in declination).…”

“…Thus, for a more reasonable determination of the orbit, we have assigned a different weight to each set of observations based on our assessment of the quality of the observations in the set. Assuming a unit weight for the old photographic observations, a weight of two was assigned to the later data by Fienga et al (2002), Veiga et al (2000) and Stone (2000Stone ( , 2001, while a weight of four was assigned to the newest CCD observations sets by Peng et al (2004) and by Qiao & Tang (2004).…”

“…The observations by Peng et al (2004) are geocentric apparent positions at the epoch of date. Our reduction of these observations included effects such as aberration, precession, and nutation.…”

“…In this paper, we used this SHAO data and several other series of new CCD data published by Veiga et al (2000), Fienga et al (2002), Stone (2000Stone ( , 2001, and Peng et al (2004), together with observations from 1904 to 1993, to obtain a new determination of Phoebe's orbit.…”

A Convenient Solution to Geometric Distortion and Its Application to Phoebe's Observations

“…Up to now, we have not taken the GD into account (in fact, we always assume that no GD exists owing to the small field of view. One can find some examples in our reference list such as Colas & Arlot 1991, Harper et al 1997, Vienne et al 2001, Peng et al 2004, 2012, and Peng & Zhang 2006. A logical way is to remove the GD effect first from all original pixel positions of reference stars and the target in a CCD frame, and then perform the abovementioned classical reduction.…”