Giorgio Parzianello

Uncertainty analysis for multi-stereo 3d shape estimation

It is described the uncertainty analysis performed for the reconstruction of a 3D shape. Multiple stereo systems are employed to measure a 3D surface with superimposed colored markers. The described procedure comprises a detailed uncertainty analysis of all the measurement phases, and the evaluated uncertainties are employed to perform a compatibility analysis of points acquired by different stereo pairs. The compatible acquired markers are statistically merged in order to obtain a measurement of a 3D shape and an evaluation of the associated uncertainty. Both the compatibility analysis and the measurement merging is based on the evaluated uncertainty.

Preliminary calibration results of the wide angle camera of the imaging instrument OSIRIS for the Rosetta mission

Rosetta is one of the cornerstone missions of the European Space Agency for having a rendezvous with the comet 67P/Churyumov-Gerasimenko in 2014. The imaging instrument on board the satellite is OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System), a cooperation among several European institutes, which consists of two cameras: a Narrow (NAC) and a Wide Angle Camera (WAC). The WAC optical design is an innovative one: it adopts an all reflecting, unvignetted and unobstructed two mirror configuration which allows to cover a 12° × 12° field of view with an F/5.6 aperture and gives a nominal contrast ratio of about 10–4. The flight model of this camera has been successfully integrated and tested in our laboratories, and finally has been integrated on the satellite which is now waiting to be launched in February 2004. In this paper we are going to describe the optical characteristics of the camera, and to summarize the results so far obtained with the preliminary calibration data. The analysis of the optical performance of this model shows a good agreement between theoretical performance and experimental results.

Design, qualification, and acceptance of the front-door mechanisms for the OSIRIS experiment of the Rosetta mission

The scope of the present document is to describe the Front Door Mechanism of Wide Angle Camera and Narrow Angle Camera of the OSIRS payload and to demonstrate the safety of the mechanism itself. To match the scientific goals it has to prevent the contamination of the telescopes during ground and in -flight operations. Moreover for the in-flight calibration the door itself will be used for the flat field of the cameras. The original design has been carried out according to optimisation techniques and successfully tested during the qualification and acceptance campaign. The results obtained demonstrated that the mechanism is fully compliant to the interface specifications and its performances are not affected by the environmental stresses and by the overall life cycling.

Thermomechanical design and optimization and acceptance of the Wide-Angle Camera for the Rosetta mission

The WAC is a telescope developed by University of Padova for the OSIRIS experiment, mainly composed by two instruments, Narrow Angle Camera and Wide Angle Camera, and the related electronics. The payload will fly on board of the Rosetta ESA scientific mission, that will be flown to encounter Comet Wirtanen after about 10 years of flight in 2013. WAC main scientific objectives are to follow structure evolution in the coma and monitor their dynamics. To fulfill scientific requirements, the optical characteristics of the WAC telescope may be summarized as follows: wide field of view of 12° X 12°, focal length of 140 mm, operate in the wave-length range 240-1000nm after 10 years in space, Encircled Energy greater than 70% over the entire FoV, contrast ratio of 10-4 to detect coma activities against a bright nucleus, minimum exposure time of 10 msec with a repeatability better than 1/500, scattered light rejection for sources inside and outside FoV. This paper deals with the design optimization of critical parts and acceptance test campaign performed to validate the thermo-structural behavior of the WAC. The functional and performance tests carried out at experiment and system level demonstrated the overall capability of the telescope to satisfy the system and scientific requirements.

Thermomechanical design optimization and acceptance of the Wide-Angle Camera for the Rosetta mission

The WAC is a telescope developed by University of Padova for the OSIRIS experiment, mainly composed by two instruments, Narrow Angle Camera and Wide Angle Camera, and the related electronics. The payload will fly on board of the Rosetta ESA scientific mission, that will be flown to encounter Comet Wirtanen after about 10 years of flight in 2013. WAC main scientific objectives are to follow structure evolution in the coma and monitor their dynamics. To fulfill scientific requirements, the optical characteristics of the WAC telescope may be summarized as follows: wide field of view of 12° X 12°, focal length of 140 mm, operate in the wave-length range 240-1000nm after 10 years in space, Encircled Energy greater than 70% over the entire FoV, contrast ratio of 10-4 to detect coma activities against a bright nucleus, minimum exposure time of 10 msec with a repeatability better than 1/500, scattered light rejection for sources inside and outside FoV. This paper deals with the design optimization of critical parts and acceptance test campaign performed to validate the thermo-structural behavior of the WAC. The functional and performance tests carried out at experiment and system level demonstrated the overall capability of the telescope to satisfy the system and scientific requirements.

Thermomechanical design optimization and acceptance of the wide-angle camera for the Rosetta mission

The WAC is a telescope developed by University of Padova for the OSIRIS experiment, mainly composed by two instruments, Narrow Angle Camera and Wide Angle Camera, and the related electronics. The payload will fly on board of the Rosetta ESA scientific mission, that will be flown to encounter Comet Wirtanen after about 10 years of flight in 2013. WAC main scientific objectives are to follow structure evolution in the coma and monitor their dynamics. To fulfill scientific requirements, the optical characteristics of the WAC telescope may be summarized as follows: wide field of view of 12° X 12°, focal length of 140 mm, operate in the wave-length range 240-1000nm after 10 years in space, Encircled Energy greater than 70% over the entire FoV, contrast ratio of 10-4 to detect coma activities against a bright nucleus, minimum exposure time of 10 msec with a repeatability better than 1/500, scattered light rejection for sources inside and outside FoV. This paper deals with the design optimization of critical parts and acceptance test campaign performed to validate the thermo-structural behavior of the WAC. The functional and performance tests carried out at experiment and system level demonstrated the overall capability of the telescope to satisfy the system and scientific requirements.