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Proceedings Paper

Preliminary results of centroiding experiment for the STEP mission
Author(s): Haitao Li; Baoquan Li; Yang Cao; Ding Chen; Ligang Li
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Paper Abstract

Search for Terrestrial Exo-Planet (STEP)[1] was originally proposed in 2013 by the National Space Science Center, Chinese Academy of Sciences, which is currently being under background engineering study phase in China. The STEP mission is a space astrometry telescope working at visible light wavelengths. The STEP aims at the nearby terrestrial planets detection through micro-arcsecond-level astrometry. Determination of the separation between star images on a detector with high precision is very important for astrometric exoplanets detection through the observation of star wobbles due to planets. The requirement of centroiding accuracy for STEP is 1e-5 pixel. A centroiding experiment have been carried out on a metrology testbed in open laboratory. In this paper, we present the preliminary results of determining the separations between star images. Without calibration of pixel positions and intra-pixel response, we have demonstrated that the standard deviation of differential centroiding is below 7.4e-3 pixel by the algorithm of linear corrected photon weighted means(LCPWM)[2,3]. For comparison, the photon weighted means(PWM) and Gauss fitting are also used in the data reduction. These results pave the way for the geometrical calibration and the intra-pixel quantum efficiency(QE) calibration of detector array equipment for micro-pixel accuracy centroiding.

Paper Details

Date Published: 5 August 2015
PDF: 6 pages
Proc. SPIE 9622, 2015 International Conference on Optical Instruments and Technology: Optoelectronic Imaging and Processing Technology, 96221A (5 August 2015); doi: 10.1117/12.2193363
Show Author Affiliations
Haitao Li, National Space Science Ctr. (China)
Key Lab. of Planetary Sciences (China)
Baoquan Li, National Space Science Ctr. (China)
Yang Cao, National Space Science Ctr. (China)
Ding Chen, National Space Science Ctr. (China)
Ligang Li, Key Lab. of Planetary Sciences (China)
Shanghai Astronomical Observatory (China)

Published in SPIE Proceedings Vol. 9622:
2015 International Conference on Optical Instruments and Technology: Optoelectronic Imaging and Processing Technology
Guangming Shi; Xuelong Li; Bormin Huang, Editor(s)

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