29 July 2016 Distortion of the pixel grid in HST WFC3/UVIS and ACS/WFC CCD detectors and its astrometric correction
Author Affiliations +
Abstract
The geometric distortion of the CCD detectors used in the Hubble Space TelescopeWide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS) instruments is characterized by both large and fine-scale distortions. The large-scale distortion, due to the complexity of the HST optical assembly, can be modeled by a high-order polynomial. The majority of fine-distortion is inherent to the CCD detectors themselves, which manifests itself as fine-scale, correlated systematic offsets in the residuals from the best-fit polynomial solution. Such systematic offsets across the CCD chip introduce astrometric errors at the level of about 0.1 pix (up to 1.5 μm within the 15 μm pixels). These fine-scale and low-amplitude distortions apparently arise from the spatial irregularities in the pixel grid. For the WFC3/UVIS CCD chips, there is a clear pattern of periodic skew in the lithographic-mask stencil imprinted onto the detector. Similar irregularities in the pixel grid of ACS/WFC CCD chips are even more pronounced by the narrow (68×2048 pixel) lithographic-mask stencil. To remove these distortions, a 2-D correction in the form of a look-up table has been developed using HST images of very dense stellar fields. The post-correction of fine-scale astrometric errors can be removed down to the level of 0.01 pix (0.15 μm) or better.
© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Vera Kozhurina-Platais, Vera Kozhurina-Platais, John Mackenty, John Mackenty, David Golimovski, David Golimovski, Marco Sirianni, Marco Sirianni, David Borncamp, David Borncamp, Jay Anderson, Jay Anderson, Norman Grogin, Norman Grogin, } "Distortion of the pixel grid in HST WFC3/UVIS and ACS/WFC CCD detectors and its astrometric correction", Proc. SPIE 9904, Space Telescopes and Instrumentation 2016: Optical, Infrared, and Millimeter Wave, 99046I (29 July 2016); doi: 10.1117/12.2233793; https://doi.org/10.1117/12.2233793
PROCEEDINGS
7 PAGES


SHARE
RELATED CONTENT

Calibration of geometric distortion in the ACS detectors
Proceedings of SPIE (February 23 2003)
High-resolution (<10-um) photon-counting intensified CCD
Proceedings of SPIE (April 24 1997)
Multiple Object Fiber Optic Spectroscopy
Proceedings of SPIE (November 15 1982)
Long-wavelength scattered-light halos in ASC CCDs
Proceedings of SPIE (July 08 1998)
The Application Of CCD Detectors To UV Imaging From A...
Proceedings of SPIE (August 15 1988)

Back to Top