The most usual method for the determination of the angular separation ρ and the magnitude difference Δm of the two components is the direct comparison of the observed diffraction pattern with a theoretical model. However, it is possible to use a deconvolution process based, for a single star, on the equation I′(x) = F′(x) * O(x), involving both the derivative of the Fresnel diffraction function for a point-like source, and that of the observed intensity. O(x) is the brightness distribution function of the occulted source.
We describe here a new method, using the integrated deconvolution process (Froeschlá, Meyer, 1983), in which we determine the variations of the apparent surface of the two sources of a double star while it is being occulted. The two sources are supposed to be of the same diameter. This method has been applied to several cases of theoretical diffraction curves with different values of ρ and Δm. Noise has been added and we have studied the effect of the signal to noise ratio on determination of the parameters ρ and Δm of the pair. A good accuracy for Δm is obtained for |Δm| ≦ 1 and noise ≦ 10%. The determination of ρ is well achieved for noise level reaching 15 %. The technique has been at last applied to the observation of the occultation of SAO 95166 made by Africano et al.(1977) leading to nearly similar results.