AAS 207th Meeting, 8-12 January 2006
Session 29 Observation Processing, Calibration and Control
Poster, Monday, 9:20am-7:00pm, January 9, 2006, Exhibit Hall

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[29.02] Subpixel Modeling for Marginally Sampled Images

K. Davidson, J. C. Martin (Univ of Minnesota), K. Ishibashi (MIT)

In many instruments, pixel sizes are somewhat too large for the underlying optical resolution. Marginal sampling degrades the data in ways that are not obvious when one views an image. This proved to be a serious obstacle in HST/STIS/CCD spectroscopy obtained for the Eta Carinae Treasury Program -- a deficiency of available software, not of the basic data quality. In order to obtain spatial resolution that was both good and consistent, we developed an appropriate technique for "sub-pixel modeling," mathematically akin to interpolation. For reasons related to missing Fourier components, this problem is not as easy as it may appear at first sight.

Our general approach is suitable for most imaging data where the ratio of pixel width to underlying p.s.f. FWHM is between about 0.3 and 1.0. "Dithering" to improve the effective pixel size is often either impractical or unnecessary, and deconvolution is of little help for this problem. Therefore our method may be useful for a variety of astronomical data images.

The Hubble Treasury Project for Eta Carinae has been supported by STScI, which is funded by NASA.

If you would like more information about this abstract, please follow the link to http://etacar.umn.edu/. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.

The author(s) of this abstract have provided an email address for comments about the abstract: kd@etacar.umn.edu

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