Gain calibration of CCD systems at VBO

Prabhu, T. P. ; Mayya, Y. D. ; Anupama, G. C. (1992) Gain calibration of CCD systems at VBO Journal of Astrophysics and Astronomy, 13 (1). pp. 129-144. ISSN 0250-6335

PDF - Publisher Version

Official URL:

Related URL:


The system gain of two CCD systems in regular use at the Vainu Bappu Observatory, Kavalur, is determined at a few gain settings. The procedure used for the determination of system gain and base-level noise is described in detail. The Photometrics CCD system at the 1-m reflector uses a Thomson-CSF TH 7882 CDA chip coated for increased ultraviolet sensitivity. The gain is programme-selected through the parameter ‘cgain’ varying between 0 and 4095 in steps of 1. The inverse system gain for this system varies almost linearly from 27.7 electrons DN-1 at cgain = 0 to 1.5 electrons DN-1 at cgain = 500. The readout noise is ≲ 11 electrons at cgain = 66. The Astromed CCD system at 2.3-m Vainu Bappu Telescope uses a GEC P8603 chip which is also coated for enhanced ultraviolet sensitivity. The amplifier gain is selected in discrete steps using switches in the controller. The inverse system gain is 4.15 electrons DN-1 at the gain setting of 9.2, and the readout noise ~ 8 electrons.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:CCD Photometry; CCD Spectroscopy; System Gain; Readout Noise
ID Code:100878
Deposited On:10 Dec 2016 12:07
Last Modified:10 Dec 2016 12:10

Repository Staff Only: item control page