M.I. Agafonov
Radiophysical Research Institute
The brightness images of celestial objects is very imporant for the study of physical processes in astrophysics. In certain cases usually with frequency decrease, the angular resolution of up-to-data synthesis radiotelescopes is insufficient. Nevertheless the observations of the objects during their Lunar occultations allows to obtain integral brightness profiles with high angular resolution. That is useful also by the observation with optical instruments. The 1-D strip-integrated projections of several occultations ingresses and regresses may be used for 2-D image reconsruction. The Lunar limb is approximated by plane screen, moving with different position angles. That is the problem similar to small foreshortened reconstructive tomography.
The first image of the Crab Nebula was presented by application of this method in [1]. But the map had the defects on the extended areas due to the used reconstruction algorithm. Trim Contour CLEAN [2] gave hope for the improvement of image quality with extended features, but it needed a study in the different practical cases. The application of this algorithm for this problem was presented in [3]. The methods of solution this deconvolution problem by poor a priori information and with few 1-D projections are presented in the outher our paper on this conference.
In this paper we present the results of numerical experiments of the images reconstruction of celestial objects with few strip-integrated projections their Lunar occultations. Besides that the maps of the brightness reconstruction with few real observational profiles. For example, our images of the Crab Nebula at 750 and 178 MHz with high resolution [4,5] and by the poor filling of the UV-plane. They was reconstructed from the profiles obtained by the observations on the 70-meter dish (RT-70) in West Crimea. This method of the digital image processing is very useful by the reconstruction in astronomy and tomography.