Novel intelligent edge detector for sonographical images
AIKED'06 Proceedings of the 5th WSEAS International Conference on Artificial Intelligence, Knowledge Engineering and Data Bases
Kalman filtering for drift correction in IR detectors
ISPRA'06 Proceedings of the 5th WSEAS International Conference on Signal Processing, Robotics and Automation
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Semiconductor bolometric detectors parameters have been analyzed within the wavelength of 100µm up to 3mm and cryogenic temperatures. From analyses and results obtained, it is shown that the values of NEP have been found to be 16.4×10-15W/Hz-1/2 and 38.466×10-15W/Hz-1/2 for cryogenic temperatures 0.5K and 5K, respectively. For the wavelength 200 µm, the maximum value of the voltage responsivity RV of the bolometer is 0.106×10-11 V/W, while for the wavelengths 1 mm, 2 mm and 3 mm, corresponding values of voltage responsivity RV of the bolometer are 0.53×10-11 V/W, 0.58×10-11 V/W and 0.637×10-11 V/W, respectively. This paper also outlines analyzes of the temperature dependency of infrared pyroelectric detectors parameters at medium wavelength (MWIR). Certain pyroelectric materials such as TGS, LiTaO3, LiNbO3, Li2SO4xH2O, BaTiO3, NaNO2, PVF2, SBN and SbSi have been analyzed within the temperature range of 273K up to 343K. Analytically it is proven that thermal time constant decreases with increasing temperature and decreasing the thickness of the detector. Analyses have shown that the smallest response time for detector which operates at room temperature 300K was achieved for the material Li2SO4×H2O with value of several milliseconds, but anyway much greater then that of photon detectors. It is also shown that NEP depends directly on circuit noises voltages. In the paper are analyzed three types of noises: thermal noise, dielectric noise, and amplifier noise. The maximum possible value of detectivity to be achieved for a MWIR infrared pyroelectric detector operates at room temperature 300K was 2.12×108 for NaNO2.