The observations are described in Refs. 1 and 4. The images are already corrected with dark frames and flat fields according to the procedure described in Ref. 1. The important observational parameters are as follows:

• SVST diameter: 47.5 cm
• SVST focal length: 22.35 m (but re-imaging changed the effective focal length)
• Diversity defocus translation along optical axis: 8.2 mm corresponding to 0.985 waves peak-to-peak
• Filter central wavelength: 469.6 nm
• Image scale: 0''.072/pixel (see Refs. 1 or 4)

These data have been used for testing out various algorithms for image reconstruction, such as phase diversity (PD) (Ref. 1-4), phase diverse speckle (PDS) (Ref. 1-4), speckle interferometry (Ref. 4), and multi-frame blind deconvolution (MFBD) (Ref. 5).

As with all data collected with the SVST, any paper that is based on these data should include the following sentence in the Acknowledgements section:

The Swedish Vacuum Solar Telescope is operated on the island of La Palma by the Royal Swedish Academy of Sciences in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

References

M. G. Löfdahl & G. B. Scharmer (1994), Wave Front Sensing and Image Restoration from Focused and Defocused Solar Images, Astronomy & Astrophysics Supplements Series, 107, pp. 243-264

M. G. Löfdahl & G. B. Scharmer (1994), Application of Phase-Diversity to Solar Images, in Proc. SPIE 2302, Image Reconstruction and Restoration, Schulz & Snyder, Eds., pp. 254 (Invited paper.)

J. H. Seldin & R. G. Paxman (1994), Phase-Diverse Speckle Reconstruction of Solar Data, in Proc. SPIE 2302, Image Reconstruction and Restoration, Schulz & Snyder, Eds., pp. 268

R. G. Paxman, J. H. Seldin, M. G. Löfdahl, G. B. Scharmer & C. U. Keller (1996), Evaluation of Phase-Diversity Techniques for Solar-Image Restoration, Astrophysical Journal, 466, pp. 1087-1099

W. van Kampen and R. G. Paxman (1998), Multi-Frame Blind Deconvolution of Infinite-Extent Objects, in Proc. SPIE 3343, Propagation and Imaging through the Atmosphere.