Attitude reconstruction of the GRANAT satellite operating in the scanning mode

Since September 1994 the GRANAT satellite has been almost continuously oper ated in the scanning mode, spinning with a period of 12 minutes around an a xis pointed roughly at Sun. The SIGMA soft gamma ray telescope, having its main axis perpendicular to the spin axis, has been accumulating photons in four broad energy bands (40-600 keV) every 4 seconds. In this paper we pres ent a method of the satellite attitude reconstruction in case of presence o f at least one strong point source in the field of view. This method makes extensive use of the knowledge of the angular response of the SIGMA telesco pe both in the precise timing analysis and in the determination of the spin axis orientation. We discuss in detail the accuracy of our approach.