GRANAT/WATCH catalogue of cosmic gamma-ray bursts: December 1989 to September 1994

We present the catalogue of gamma-ray bursts observed with the WATCH all-sky monitor on board the GRANAT satellite during the period December 1989 to September 1994. The cosmic origin of 95 bursts comprising the catalogue is confirmed either by their localization with WATCH or by their detection with other GRB experiments. For each burst its time history and information on its intensity in the two energy ranges 8-20 keV and 20-60 keV are presented. Most events show hardening of the energy spectrum near the burst peak. In part of the bursts an X-ray precursor or a tail is seen at 8-20 keV. We have determined the celestial positions of the sources of 47 bursts. Their localization regions (at 3-sigma confidence level) are equivalent in area to circles with radii ranging from 0.2 to 1.6 deg. The burst sources appear isotropically distributed on the sky on large angular scales.Comment: 18 pages (including 3 tables and 7 figures), LaTeX, l-aa style. Accepted by Astronomy and Astrophysics Suppl. Serie

Restoration of Deterministic and Interference Distorted Signals and Images with Use of the Generalized Spectra Based on Orthogonal Polynomials and Functions

Restoration algorithms of signals and images on the basis of their generalized spectra in bases of orthogonal polynomials and functions at absence and presence of random distortions have been examined. It is shown that in absence of hindrances the number of coefficients of the generalized spectrum of a restored signal (image) is determined by the desired approximation error at use of one or another metrics of functional space. If hindrances take place then there is an optimum number of coefficients of the generalized spectrum for signal (image) restoration. Working data of the proposed algorithms for various types of useful signals have been illustrated