Accounting for exposure time with two-point correction of fixed pattern noise of a matrix photodetector

Abstract

The article discusses the issues of eliminating the geometric noise of infrared matrix sensors, which is still an urgent task related to the need to detect low-contrast objects in the video surveillance field against the background of fluctuating noise and deterministic interference. The compensatory method of combating geometric noise is considered in detail, in particular, the so-called two-point correction based on the preliminary factory calibration of the matrix sensor at a fixed exposure time. Changing the exposure time of the matrix sensor in the process of informative illumination in relation to the exposure time used at the calibration stage leads to a compensation error, which manifests itself in the form of fine-grained noise in the image. In this regard, the methods of geometric noise compensation, taking into account possible changes in the exposure time of the matrix sensor during informative illumination, considered in the article, are of practical interest to developers of this class of equipment. The article discusses in sufficient detail the features of accounting for exposure time from the point of view of the influence of additive (caused by uneven thermal emission in the elements of the matrix sensor) and multiplicative (caused by uneven sensitivity of the elements of the matrix sensor) components of geometric noise, and the results of computer modeling are presented, recommendations for use are given.