Fast Dark Signal Measurements of SVOM VT CCDs Using the Vertical Gradient of Dark Field Images
This paper describes a fast technique for estimating the dark signals of the charge coupled devices (CCDs) of the visible telescope (VT) onboard the space multi-band variable object monitor (SVOM). It is based on the vertical gradient in the dark field images of the frame transfer CCDs. During the p...
Main Authors: | , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
MDPI AG
2021-04-01
|
Series: | Photonics |
Subjects: | |
Online Access: | https://www.mdpi.com/2304-6732/8/4/132 |
id |
doaj-af67d455d3bb44d1b27b63eace378520 |
---|---|
record_format |
Article |
spelling |
doaj-af67d455d3bb44d1b27b63eace3785202021-04-20T23:05:52ZengMDPI AGPhotonics2304-67322021-04-01813213210.3390/photonics8040132Fast Dark Signal Measurements of SVOM VT CCDs Using the Vertical Gradient of Dark Field ImagesYue Pan0Xuewu Fan1Hui Zhao2Yulei Qiu3Wei Gao4Jian Zhang5Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, ChinaXi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, ChinaXi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, ChinaNational Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, ChinaXi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, ChinaXi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, ChinaThis paper describes a fast technique for estimating the dark signals of the charge coupled devices (CCDs) of the visible telescope (VT) onboard the space multi-band variable object monitor (SVOM). It is based on the vertical gradient in the dark field images of the frame transfer CCDs. During the process of frame clear, exposure, frame transfer and readout, the characteristic of dark signal accumulation is analyzed firstly. Next, the linear fitting method is used to fit the signal level of the dark field image in the vertical direction, and the slope of the fitting line represents the dark signal factor. This technique only needs one dark field image and can be used for simple and efficient dark signal measurements of frame transfer CCDs. Besides, an experiment of detecting dark signals as a function of temperature based on the fast technique has been carried out. Making use of the Shockley-Hall-Read theory, two curve fitting formulas are adopted to the experimental results for VT Advanced Inverted Mode Operation (AIMO) CCD and VT Non-Inverted Mode Operation (NIMO) CCD respectively. The experimental results and the formulas are used to determine the optimal on-orbit cooling temperature of VT CCDs.https://www.mdpi.com/2304-6732/8/4/132charge coupled device (CCD)CCD characterizationdark signalvertical gradientSVOM VT |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Yue Pan Xuewu Fan Hui Zhao Yulei Qiu Wei Gao Jian Zhang |
spellingShingle |
Yue Pan Xuewu Fan Hui Zhao Yulei Qiu Wei Gao Jian Zhang Fast Dark Signal Measurements of SVOM VT CCDs Using the Vertical Gradient of Dark Field Images Photonics charge coupled device (CCD) CCD characterization dark signal vertical gradient SVOM VT |
author_facet |
Yue Pan Xuewu Fan Hui Zhao Yulei Qiu Wei Gao Jian Zhang |
author_sort |
Yue Pan |
title |
Fast Dark Signal Measurements of SVOM VT CCDs Using the Vertical Gradient of Dark Field Images |
title_short |
Fast Dark Signal Measurements of SVOM VT CCDs Using the Vertical Gradient of Dark Field Images |
title_full |
Fast Dark Signal Measurements of SVOM VT CCDs Using the Vertical Gradient of Dark Field Images |
title_fullStr |
Fast Dark Signal Measurements of SVOM VT CCDs Using the Vertical Gradient of Dark Field Images |
title_full_unstemmed |
Fast Dark Signal Measurements of SVOM VT CCDs Using the Vertical Gradient of Dark Field Images |
title_sort |
fast dark signal measurements of svom vt ccds using the vertical gradient of dark field images |
publisher |
MDPI AG |
series |
Photonics |
issn |
2304-6732 |
publishDate |
2021-04-01 |
description |
This paper describes a fast technique for estimating the dark signals of the charge coupled devices (CCDs) of the visible telescope (VT) onboard the space multi-band variable object monitor (SVOM). It is based on the vertical gradient in the dark field images of the frame transfer CCDs. During the process of frame clear, exposure, frame transfer and readout, the characteristic of dark signal accumulation is analyzed firstly. Next, the linear fitting method is used to fit the signal level of the dark field image in the vertical direction, and the slope of the fitting line represents the dark signal factor. This technique only needs one dark field image and can be used for simple and efficient dark signal measurements of frame transfer CCDs. Besides, an experiment of detecting dark signals as a function of temperature based on the fast technique has been carried out. Making use of the Shockley-Hall-Read theory, two curve fitting formulas are adopted to the experimental results for VT Advanced Inverted Mode Operation (AIMO) CCD and VT Non-Inverted Mode Operation (NIMO) CCD respectively. The experimental results and the formulas are used to determine the optimal on-orbit cooling temperature of VT CCDs. |
topic |
charge coupled device (CCD) CCD characterization dark signal vertical gradient SVOM VT |
url |
https://www.mdpi.com/2304-6732/8/4/132 |
work_keys_str_mv |
AT yuepan fastdarksignalmeasurementsofsvomvtccdsusingtheverticalgradientofdarkfieldimages AT xuewufan fastdarksignalmeasurementsofsvomvtccdsusingtheverticalgradientofdarkfieldimages AT huizhao fastdarksignalmeasurementsofsvomvtccdsusingtheverticalgradientofdarkfieldimages AT yuleiqiu fastdarksignalmeasurementsofsvomvtccdsusingtheverticalgradientofdarkfieldimages AT weigao fastdarksignalmeasurementsofsvomvtccdsusingtheverticalgradientofdarkfieldimages AT jianzhang fastdarksignalmeasurementsofsvomvtccdsusingtheverticalgradientofdarkfieldimages |
_version_ |
1721517172300185600 |