The fisheye of the comet interceptor's EnVisS camera
Loading...
Access rights
openAccess
Journal Title
Journal ISSN
Volume Title
Conference article
This publication is imported from Aalto University research portal.
View publication in the Research portal
View/Open full text file from the Research portal
Other link related to publication
View publication in the Research portal
View/Open full text file from the Research portal
Other link related to publication
Date
2021
Major/Subject
Mcode
Degree programme
Language
en
Pages
8
Series
Proceedings of SPIE - The International Society for Optical Engineering, Volume 11852
Abstract
Entire Visible Sky (EnVisS) camera is one of the payload proposed for the ESA selected F-Class mission Comet Interceptor. The main aim of the mission is the study of a dynamic new comet, or an interstellar object, entering the inner solar system for the first time. The Comet Interceptor mission is conceived to be composed of three spacecraft: a parent spacecraft A and two, spacecraft B1 and B2, dedicated to a close and risky fly-by. EnVisS will be mounted on spacecraft B2, which is foreseen to be spin-stabilized. The EnVisS camera is designed to capture the entire sky in some visible wavelength bands while the spacecraft pass through the comet's coma. EnVisS optical head is composed of a fisheye lens with a field of view of 180° x 40° coupled with an imaging detector equipped with both band-pass and polarimetric filters. The design of fisheye lenses requires to take into account some issues typical of very wide-angle lenses. The fundamental origin of the optical problems resides on the entrance pupil shift atlarge angle, where the paraxial approximation is no more valid: chief rays angles on the object side are not preserved passing through the optics preceding the aperture stop (fore-optics). This effect produces an anamorphic deformation of the image on the focal plane, i.e. the focal length is changing along the elevation angles. Tracing the rays appropriately requires some effort by the designer. It has to be considered that distortion, including anamorphism, is an aberration that does not affect the quality of a point source image, thus it can be present also in well corrected lenses. In this paper the optical design of the fisheye lens, that will be mounted on the EnVisS camera for the ESA F-class "Comet Interceptor" mission, will be presented together with the initial optical requirements and the final expected optical performances.Description
Funding Information: This work has been funded by ASI (contract n. 2020-4-HH.0) for the Italian participation to the phase-0 study of ESA Comet Interceptor EnVisS camera. GHJ is grateful to the UK Space Agency for support. GB is supported by a UK Science and Technology Facilities Council (STFC) PhD studentship. Publisher Copyright: © 2021 ESA and CNES
Keywords
Astronomical imaging, Fisheye lenses, Lens mapping function, Wide angle lenses
Other note
Citation
Pernechele , C , da Deppo , V , Consolaro , L , Jones , G H , Brydon , G , Zuppella , P , Chioetto , P , Nordera , S , Lara , L & Slavinskis , A 2021 , ' The fisheye of the comet interceptor's EnVisS camera ' , Proceedings of SPIE - The International Society for Optical Engineering , vol. 11852 , 118524V . https://doi.org/10.1117/12.2599817
