AUTOCORRELATION CENTRAL VALUE IN CLIPPED PHOTON-COUNTING DETECTION FROM THE MOMENTS OF THE TOTAL NUMBER OF COUNTS

Many existing photon-limited image detectors are not able to distingui sh whether a photoevent in one pixel comes from single or multiple eve nts, and the output of such devices consists only of a series of binar y values denoting presence or absence of counts in each pixel. The cou nts are therefore clipped, and this leads to a hole in the Autocorrela tion estimate that must be removed for image recovery applications. In this letter, two methods to obtain the Autocorrelation central value from clipped photon-counting data are presented. They are based on the statistical analysis of the total number of counts in one frame. One of the methods requires a smaller number of frames to provide good sta tistical accuracy while the other has a wider intensity range of appli cability.