A&A Supplement Series, Vol. 126, November II 1997, 177-181

Received April 28; accepted February 20, 1997

Determination of the atmospheric point spread function by a parameter search

V. Krishnakumar and P. Venkatakrishnan

Indian Institute of Astrophysics, Bangalore 560034, India

Abstract:

The result of blind deconvolution is a reconstructed image that has non positive intensities. The number of these non positive pixels has been used as an estimator for the departure from a perfect reconstruction. Simulations of reconstruction of objects convolved with a kernel having one or two parameters are shown to demonstrate the efficiency of the estimator. We thus present a technique of determining the unknown parameters of the point spread function by searching for the point in parameter space with the lowest number of nonpositive pixels. It is also shown that the parameters of the convolving kernel can be obtained even in the presence of noise. This method was validated using a long exposure image of NGC 1409.

keywords: techniques: image processing -- atmospheric effects -- globular clusters: NGC 1409

• 1. Introduction
• 2. Technique for recovering the point spread function
• 3. Simulations
• 4. Conclusions
• Appendix 1
• References