Results 141 to 150 of about 206,674 (200)

Thermal drift compensation method for microbolometer thermal cameras

Applied Optics, 2012
We propose a new method of compensation for drifts in thermal cameras using a filter in place of a shutter. The latter method requires periodically closing the camera, thus causing the images to appear frozen frequently. Our technique of replacing the shutter with a filter eliminates this frozen image problem. In this paper we discuss the principles of
Robert, Olbrycht, Bogusław, Więcek, Gilbert, De Mey   +2 more
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A thermally compensated microbarograph

Journal of Physics E: Scientific Instruments, 1982
Microbarographs are made virtually temperature independent by procedures including installation of a temperature-dependent compensating electronic system.
G L Goodwin, C R Flaherty
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Thermal blooming compensation instabilities

Journal of the Optical Society of America A, 1989
A general model is developed for the time-dependent growth of small perturbations in thermally bloomed beams with and without correction. Intensity and phase every where along the path of an intense forward beam and a weak backward beam are determined from the initial beam and path conditions by five time-dependent Green functions.
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Apparatus and its principle for thermal aberration compensation

Applied Optics, 2022
Thermal aberrations caused by absorption of laser beams degrade the image quality of exposure tools during the working process. Many compensators, such as lens movement or lens deformation, are used to compensate for low-order thermal aberrations of optical systems.
Xinfeng, Yu, Huaijiang, Yang, Mingyang, Ni   +2 more
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Thermal-blooming compensation using the CLASP system

Applied Optics, 1978
A closed-loop system for phase compensation of thermal blooming has been designed and tested. This system-called CLASP for closed-loop adaptive single parameter-is a single-mode outgoing-wave dither system. CLASP has demonstrated stable convergence to the optimum thermal-blooming-correction amplitude in a laboratory experiment.
C A, Primmerman, F B, Johnson, I, Wigdor
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Thermal effects and thermal compensation in the OSIRIS camera

SPIE Proceedings, 2003
Tight stability requirements for the imager/spectrograph OSIRIS (a Day One optical instrument for the GTC telescope) demand a careful treatment of thermal effects within the OSIRIS camera. Mostly due to the thermal response of refraction indices of its glasses (and not so much to curvature, spacing or thickness variations of the lenses), the camera ...
J. Jesus Gonzalez, Carlos Tejada, Alejandro Farah, Jose L. Rasilla, F. Javier Fuentes   +4 more
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Thermal blooming compensation with adaptive optics

Optics Letters, 1978
A multidither adaptive optical system has been used to correct for thermal blooming distortions. Stable correction factors of from 1.3 to 4 have been observed. Turbulence correction in the presence of blooming has also been observed. It is suggested that the geometry of the blooming scenario (location of absorption region, slue rate, etc.) and the ...
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Thermal-Frequency-Drift Compensation

Proceedings of the IRE, 1942
The conditions necessary for minimizing frequency drift with variation of ambient temperature are examined for various types of circuits. In fixed-tuned circuits the drift can be eliminated by a comparatively simple adjustment of the temperature coefficient of capacitance.
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Thermally compensated crystal oscillators

Journal of the British Institution of Radio Engineers, 1958
The paper describes a new approach to the problem of “frequency-versus-temperature” stability. The principle involved is particularly suitable for the special requirements of mobile and portable communications equipment. In contrast to oven-controlled crystal oscifiators the technique requires neither the expenditure of power nor the use of thermostats
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Thermal variation and pressure compensated emitters

Agricultural Water Management, 2016
Abstract A number of factors may contribute to the non-uniformity of an unclogged drip irrigation (DI) system. It is understood that DI emitters respond to the thermal changes in the environment resulting in variable flow-rates. This study investigates the effect of thermal variation (air and water) on the performance of inline pressure compensated ...
M.M.H. Oliver, Guna Alankerage Hewa, David Pezzaniti   +2 more
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