The Fredholm equation of the first kind is commonly used in tasks of compensation for Point Spread Function (PSF)
distortion. However, there exists some contradiction. Namely, the distortion in any definite point depends on a small
amount of adjacent points. Meanwhile, the task of compensation is set forth for image as a whole, i.e. for a large amount
of points. The ultra-resolution method does not make use of the Fredholm equation of the first kind. The PSF distortions
are compensated point by point [1,2]. The method can be used at low signal-to-noise ratio. The characterization of ultraresolution
method is connected with the investigation of the value of compensated distortions in dependence on the noise
level and on the pass band frequency of the method.
Application of resolving function for object-target as a special PSF gives us a principally new approach to the targeting
problem. Characterization in this case helps us to choose the accuracy of indication in the point of the target.