10 December 2001 Stray light evaluation of the Ultraviolet and Visible-light Coronagraph Imager (UVCI) rocket prototype
Author Affiliations +
The Ultraviolet and Visible-light Coronagraph Imager (UVCI) proposed for the European Space Agency (ESA) Solar Orbiter mission, is designed to image the visible and the ultraviolet coronal emissions, in order to diagnose the solar corona. The UVCI is an externally occulted reflection coronagraph that obtains monochromatic images in the neutral hydrogen HI 121.6 nm and in the single ionized helium HeII 30.4 nm lines, and measures the polarized brightness (pB) of the K-corona in broadband visible light. One of the most stringent requirements in the design of a coronagraph is the stray light rejection. The stray light is produced by solar disk radiation which is several order of magnitude brighter than the coronal radiation in both visible and UV. The solar disk radiation enters the instrument through the external aperture and stray light is produced by diffraction off the edges of the apertures and of the optical components, non-specular reflections off the mirror surfaces, and scattering off the mechanical structure. In this paper, the features in the optical design that contribute to the stray light reduction are described, and an analysis of all possible stray light contributions is performed on the optical configuration of the UVCI sounding rocket prototype (UVC-SR). From this analysis, a stray light model has been developed and its results are compared with the minimum measurable signal expected from the solar corona.
© (2001) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Marco Romoli, Federico Landini, Silvano Fineschi, Daniele Gardiol, Giampiero Naletto, Marco Malvezzi, Giuseppe Tondello, Giancarlo C. Noci, Ester Antonucci, "Stray light evaluation of the Ultraviolet and Visible-light Coronagraph Imager (UVCI) rocket prototype", Proc. SPIE 4498, UV/EUV and Visible Space Instrumentation for Astronomy and Solar Physics, (10 December 2001); doi: 10.1117/12.450076; https://doi.org/10.1117/12.450076

Back to Top