COMPUTER-SIMULATION OF SUPERRESOLUTION POINT-SOURCE IMAGE DETECTION

We present a computer simulation of the analysis of an ''in-focus'' tw o-dimensional (2-D) Airy disk. Two competing methods are used to calcu late the coordinates of the center of this point spread function image . The first one is the classical technique that relies on the 2-D ''ce ntroid'' of the image, and the second one is a more original method th at uses the frequency dependence of the argument of the Fourier transf orm. Comparative simulations show that the latter technique [Fourier p hase shift (FPS)] allows us to obtain a very good precision of better than 1% of a pixel spacing after quantization. Perturbations such as d e offset reduction, quantization noise, and additive Gaussian noise ar e introduced in the simulation. The results show that there is an impr oved perturbation immunity for the FPS method.