SENSITIVITY TEMPERATURE DEPENDENCE RESEARCH OF TV-CAMERAS BASED ON SILICON MATRIXES
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For citation: Starchenko A.N., Filippov V.G., Yugai Yu.A. Sensitivity temperature dependence research of TV-cameras based on silicon matrixes. Scientific and Technical Journal of Information Technologies, Mechanics and Optics , 2017, vol. 17, no. 4, pp. 628–634 (in Russian). doi: 10.17586/2226-1494-2017-17-4-628-634
Subject of Research.The research is dedicated to the analysis of sensitivity change patterns of the cameras based on silicon CMOS-matrixes in various ambient temperatures. This information is necessary for the correct camera application for photometric measurements in-situ. The paper deals with studies of sensitivity variations of two digital cameras with different silicon CMOS matrixes in visible and near IR regions of the spectrum at temperature change. Method. Due to practical restrictions the temperature changes were recorded in separate spectral intervals important for practical use of the cameras. The experiments were carried out with the use of a climatic chamber, providing change and keeping the temperature range from minus 40 to plus 50 °C at a pitch of 10 оС. Two cameras were chosen for research: VAC-135-IP with OmniVision OV9121 matrix and VAC-248-IP with OnSemiconductor VITA2000 matrix. The two tested devices were placed in a climatic chamber at the same time and illuminated by one radiation source with a color temperature about 3000 K in order to eliminate a number of methodological errors. Main Results. The temperature dependence of the signals was shown to be linear and the matrixes sensitivities were determined. The results obtained are consistent with theoretical views, in general. The coefficients of thermal sensitivity were computed by these dependencies. It is shown that the greatest affect of temperature on the sensitivity occurs in the area (0.7–1.1) mkm. Temperature coefficients of sensitivity increase with the downward radiation wavelength increase. The experiments carried out have shown that it is necessary to take into account the changes in temperature sensitivity of silicon matrixes in the red and near in IR regions of the spectrum. The effect reveals itself in a clearly negative way in cameras with an amplitude resolution of 10-12 bits used for aerospace and space spectrozonal photography. Practical Relevance. The obtained values of temperature sensitivity coefficients enable to correct the received signals by means of a calculation and to obtain more reliable information on the photometric properties of scenes and objects.