Among the scientific objectives addressed by the Radio Science Experiment hosted on board the ESA mission BepiColombo is the retrieval of the rotational state of planet Mercury. In fact, the estimation of the obliquity and the libra-tions amplitude were proven to be fundamental for constraining the interior composition of Mercury1. This is accomplished by the Mercury Orbiter Radio science Experiment via a strict interaction among different payloads thus mak-ing the experiment particularly challenging. The underlying idea consists in capturing images of the same landmark on the surface of the planet in different epochs in order to observe a displacement of the identified features with respect to a nominal rotation which allows to esti-mate the rotational parameters. Observations must be planned accurately in or-der to obtain image pairs carrying the highest information content for the fol-lowing estimation process. This is not a trivial task especially in light of the several constraints involved. First of all, the peculiar Mercury’s dynamic char-acterized by a 3:2 spin orbit resonance and the dependence of librations ampli-tude on Mercury’s mean anomaly leads to the fact that under the same illumi-nation conditions no libration is observed. Another delicate issue is represented by the pattern matching process between image pairs for which the lowest cor-relation errors are desired. Although modern algorithms are able to reach sub-pixels accuracies, different strategies must be implemented according to the type of images to be matched, especially for what concerns illumination and scale variations, and the type of features to be detected. Due to the many physical and operational constraints involved in this complex experiment, an end-to-end simulator of the experiment was designed with the final objective of establishing the optimal observations planning. In particular, this paper will focus on the software implemented for the generation of a map and database of the global observations, and on postprocessing simulations fundamental to lead the image pairs selection process.
A. Palli, P. Tortora (2012). Selection of Mercury’s Surface Features Coordinates for the BepiColombo Rotation Experiment. SAN DIEGO, CALIFORNIA : Univelt, Inc..
Selection of Mercury’s Surface Features Coordinates for the BepiColombo Rotation Experiment
PALLI, ALESSANDRA;TORTORA, PAOLO
2012
Abstract
Among the scientific objectives addressed by the Radio Science Experiment hosted on board the ESA mission BepiColombo is the retrieval of the rotational state of planet Mercury. In fact, the estimation of the obliquity and the libra-tions amplitude were proven to be fundamental for constraining the interior composition of Mercury1. This is accomplished by the Mercury Orbiter Radio science Experiment via a strict interaction among different payloads thus mak-ing the experiment particularly challenging. The underlying idea consists in capturing images of the same landmark on the surface of the planet in different epochs in order to observe a displacement of the identified features with respect to a nominal rotation which allows to esti-mate the rotational parameters. Observations must be planned accurately in or-der to obtain image pairs carrying the highest information content for the fol-lowing estimation process. This is not a trivial task especially in light of the several constraints involved. First of all, the peculiar Mercury’s dynamic char-acterized by a 3:2 spin orbit resonance and the dependence of librations ampli-tude on Mercury’s mean anomaly leads to the fact that under the same illumi-nation conditions no libration is observed. Another delicate issue is represented by the pattern matching process between image pairs for which the lowest cor-relation errors are desired. Although modern algorithms are able to reach sub-pixels accuracies, different strategies must be implemented according to the type of images to be matched, especially for what concerns illumination and scale variations, and the type of features to be detected. Due to the many physical and operational constraints involved in this complex experiment, an end-to-end simulator of the experiment was designed with the final objective of establishing the optimal observations planning. In particular, this paper will focus on the software implemented for the generation of a map and database of the global observations, and on postprocessing simulations fundamental to lead the image pairs selection process.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
