A Non-linearity Correction Method for Calibration of Optical Sensor at Low Level Light
This paper describes a methodology developed for calibrating optical detector for light engineering, especially for devices used at low level light, including auroral imager, star sensor, astronomical camera and similar optical instruments. In order to know the physical meaning of optical sensor output, calibration is the first and most important process in a complete analysis of observed data. It is found that optical sensors, like CCDs, are not perfectly linear systems as they were assumed. After bias frame subtraction, the number of ADU counts is not exactly proportional to the number of incident photons. A key component of this paper is non-linearity correction. One of current applications using this method is auroral imager which is used for measuring aurora, high-altitude clouds, and other atmospheric optical objects light intensity, which is the first step to complete an optical object tomography simulation.
KeywordsCalibration Low Light Optical Sensor
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- 1.Steen, A., Brändström, U.: A multi-station ground-based imaging system at high latitudes. STEP Int. Newsl. 3, 11–14 (1993)Google Scholar
- 2.Gustavsson, B.: Three Dimensional Imaging of Aurora and Airglow, PhD thesis (2000)Google Scholar
- 3.Brändström, U.: IRF Scientific Report 179 (2003) Google Scholar
- 4.Lauche, H., Widell, O.: Intercalibration of low light level sources. In: Proc. of 27th Annual European Meeting on Atmospheric Studies by Optical Methods. Meteorological institution, Stockholm university, Stockholm, Sweden (2000b)Google Scholar
- 5.Widell, O., Henricson, H.: Intercalibration of low light level sources. In: Proc. of 28th Annual European Meeting on Atmospheric Studies by Optical Methods, Oulu, Finland, Sodankyla Geophysical Observatory (2001)Google Scholar