INVESTIGATION OF AN OPTOELECTRONIC SYSTEM FOR DETECTING SMALL-SIZED AND INCONSPICUOUS OBJECTSUNDER THE INFLUENCE OF GEOMETRIC NOISE OF A MATRIX PHOTODETECTOR

Abstract

The basis for reducing the accuracy of obtaining coordinate and non-coordinate information in an optical-electronic system with a matrix photo detector is geometric noise caused by uneven sensitivity and topology of the photodiode matrix. The presented mathematical model of a matrix photodetector based on the geometric array of photodiodes takes into account the main geometric parameters of the topology of the photodiode matrix. The questions of the accuracy of determining coordinates for small-sized and hardly noticeable light objects comparable to the size of a raster by the method of continuous wavelet transforms of signals from a photodiode array are considered. The possibility of geometric noise filtering by the method of continuous wavelet transform is shown by excluding from the scalogram the range of wavelet transform scales corresponding to the period of the geometric raster. It is shown that the algorithms of continuous wavelet transforms provide an increase in the accuracy of extracting the information component of small-sized and inconspicuous objects observed by an optoelectronic system with a matrix photodetector. A software prototype in the NI LabVIEW application development environment is presented. A technique has been developed for carrying out computational experiments to estimate the accuracy of determining the coordinate depending on the position of a small-sized light object relative to the topological raster of a matrix photodetector, as well as to estimate the detection sensitivity at a given noise level of photodiodes. An assessment of the accuracy of obtaining coordinate and non-coordinate information by a matrix photodetector under the influence of geometric noise has been carried out. It has been established that the filtering of geometric noise provides an increase in the detectivity of the optoelectronic system for detecting small-sized and inconspicuous light objects by more than one and a half times.