OSA's Digital Library

Journal of the Optical Society of America

Journal of the Optical Society of America

  • Vol. 56, Iss. 10 — Oct. 1, 1966
  • pp: 1385–1389

Intrinsic Limitations in Locating Photographic Star Images

EDWARD J. FARRELL  »View Author Affiliations

JOSA, Vol. 56, Issue 10, pp. 1385-1389 (1966)

View Full Text Article

Acrobat PDF (557 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



The accuracy of locating weak photographic star images is described from a theoretical viewpoint. The objective is to determine the accuracy limitations imposed by the granular nature of the photographic image, by background radiation, and by image size and shape. After selecting models for both saturated and unsaturated images, lower bounds are derived for the rms location errors. These relationships are based on results developed for photoelectric images. The bounds apply to every method of interrogating the photographic images, and thus represent intrinsic limitations. For unsaturated images, the bound is a monotone function of the image “spread” σ; it is approximately proportional to σ(c-lnσ) where c is a constant. For saturated images, the bound is not necessarily a monotone function of the image spread. The bound may decrease as the image spread increases. The error bounds are compared to experimental errors. For an eighteenth-magnitude star, the bound is 70% of the experimental errors observed with plates from the 48-in. Schmidt telescope on Palomar.

EDWARD J. FARRELL, "Intrinsic Limitations in Locating Photographic Star Images," J. Opt. Soc. Am. 56, 1385-1389 (1966)

Sort:  Author  |  Journal  |  Reset


  1. W. A. Baum, [Chapter 1] in Astronomical Techniques, edited by W. A. Hiltner (University of Chicago Press, Chicago, Illinois, 1962); J. C. Marchant and A. G. Millikan, J. Opt. Soc. Am. 55, 907 (1965); R. C. Jones, J. Opt. Soc. Am. 51, 1159 (1961).
  2. The effect of scanning a gaussian-shaped image with a rectangular aperture is described by E. J. Farrell and C. D. Zimmerman, in Optical and Electro-Optical Information Processing, edited by J. T. Tippett el al. (MIT Press, Cambridge, Massachusetts, 1965).
  3. W. A. Baum, Trans. Int. Astr. Un. 9, 681 (1955).
  4. E. J. Farrell, J. Opt. Soc. Am. 56, 578 (1966).
  5. Derivation given in reference cited in Ref. 4.
  6. See reference cited in Ref. 1.
  7. N. M. Evensen and R. E. Mohr investigated the characteristics of star images as a complement to a proper-motion survey being conducted by Professor Willem Luyten at the University of Minnesota.
  8. This relationship is developed by B. E. Bayer, J. Opt. Soc. Am. 54, 1485 (1964).
  9. For small values of r, I0(r)≍r/8.

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited