Gaia Data Release 1 : On-orbit performance of the Gaia CCDs at L2
(2016) In Astronomy and Astrophysics 595.- Abstract
The European Space Agency's Gaia satellite was launched into orbit around L2 in December 2013 with a payload containing 106 large-format scientific CCDs. The primary goal of the mission is to repeatedly obtain high-precision astrometric and photometric measurements of one thousand million stars over the course of five years. The scientific value of the down-linked data, and the operation of the onboard autonomous detection chain, relies on the high performance of the detectors. As Gaia slowly rotates and scans the sky, the CCDs are continuously operated in a mode where the line clock rate and the satellite rotation spin-rate are in synchronisation. Nominal mission operations began in July 2014 and the first data release is being... (More)
The European Space Agency's Gaia satellite was launched into orbit around L2 in December 2013 with a payload containing 106 large-format scientific CCDs. The primary goal of the mission is to repeatedly obtain high-precision astrometric and photometric measurements of one thousand million stars over the course of five years. The scientific value of the down-linked data, and the operation of the onboard autonomous detection chain, relies on the high performance of the detectors. As Gaia slowly rotates and scans the sky, the CCDs are continuously operated in a mode where the line clock rate and the satellite rotation spin-rate are in synchronisation. Nominal mission operations began in July 2014 and the first data release is being prepared for release at the end of Summer 2016. In this paper we present an overview of the focal plane, the detector system, and strategies for on-orbit performance monitoring of the system. This is followed by a presentation of the performance results based on analysis of data acquired during a two-year window beginning at payload switch-on. Results for parameters such as readout noise and electronic offset behaviour are presented and we pay particular attention to the effects of the L2 radiation environment on the devices. The radiation-induced degradation in the charge transfer efficiency (CTE) in the (parallel) scan direction is clearly diagnosed; however, an extrapolation shows that charge transfer inefficiency (CTI) effects at end of mission will be approximately an order of magnitude less than predicted pre-flight. It is shown that the CTI in the serial register (horizontal direction) is still dominated by the traps inherent to the manufacturing process and that the radiation-induced degradation so far is only a few per cent. We also present results on the tracking of ionising radiation damage and hot pixel evolution. Finally, we summarise some of the detector effects discovered on-orbit which are still being investigated.
(Less)
- author
- Crowley, C.
; Kohley, R.
; Hambly, N. C.
; Davidson, M.
; Abreu, A.
; Van Leeuwen, F.
; Fabricius, C.
; Seabroke, G.
; De Bruijne, J. H J
; Short, A.
; Lindegren, L.
LU
; Brown, A. G A
; Sarri, G.
; Gare, P.
; Prusti, T.
; Prod'homme, T.
; Mora, A.
; Martín-Fleitas, J.
; Raison, F.
; Lammers, U.
; O'Mullane, W.
and Jansen, F.
(Less) - organization
- publishing date
- 2016-11-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Astrometry, Instrumentation: detectors, Methods: data analysis, Space vehicles: instruments
- in
- Astronomy and Astrophysics
- volume
- 595
- article number
- A6
- publisher
- EDP Sciences
- external identifiers
-
- wos:000388573500093
- scopus:84998673854
- ISSN
- 0004-6361
- DOI
- 10.1051/0004-6361/201628990
- language
- English
- LU publication?
- yes
- id
- 61cf5fc4-7bad-47b8-91de-b901199a5ad3
- date added to LUP
- 2016-12-20 10:57:43
- date last changed
- 2025-03-23 00:45:38
@article{61cf5fc4-7bad-47b8-91de-b901199a5ad3,
abstract = {{<p>The European Space Agency's Gaia satellite was launched into orbit around L2 in December 2013 with a payload containing 106 large-format scientific CCDs. The primary goal of the mission is to repeatedly obtain high-precision astrometric and photometric measurements of one thousand million stars over the course of five years. The scientific value of the down-linked data, and the operation of the onboard autonomous detection chain, relies on the high performance of the detectors. As Gaia slowly rotates and scans the sky, the CCDs are continuously operated in a mode where the line clock rate and the satellite rotation spin-rate are in synchronisation. Nominal mission operations began in July 2014 and the first data release is being prepared for release at the end of Summer 2016. In this paper we present an overview of the focal plane, the detector system, and strategies for on-orbit performance monitoring of the system. This is followed by a presentation of the performance results based on analysis of data acquired during a two-year window beginning at payload switch-on. Results for parameters such as readout noise and electronic offset behaviour are presented and we pay particular attention to the effects of the L2 radiation environment on the devices. The radiation-induced degradation in the charge transfer efficiency (CTE) in the (parallel) scan direction is clearly diagnosed; however, an extrapolation shows that charge transfer inefficiency (CTI) effects at end of mission will be approximately an order of magnitude less than predicted pre-flight. It is shown that the CTI in the serial register (horizontal direction) is still dominated by the traps inherent to the manufacturing process and that the radiation-induced degradation so far is only a few per cent. We also present results on the tracking of ionising radiation damage and hot pixel evolution. Finally, we summarise some of the detector effects discovered on-orbit which are still being investigated.</p>}},
author = {{Crowley, C. and Kohley, R. and Hambly, N. C. and Davidson, M. and Abreu, A. and Van Leeuwen, F. and Fabricius, C. and Seabroke, G. and De Bruijne, J. H J and Short, A. and Lindegren, L. and Brown, A. G A and Sarri, G. and Gare, P. and Prusti, T. and Prod'homme, T. and Mora, A. and Martín-Fleitas, J. and Raison, F. and Lammers, U. and O'Mullane, W. and Jansen, F.}},
issn = {{0004-6361}},
keywords = {{Astrometry; Instrumentation: detectors; Methods: data analysis; Space vehicles: instruments}},
language = {{eng}},
month = {{11}},
publisher = {{EDP Sciences}},
series = {{Astronomy and Astrophysics}},
title = {{Gaia Data Release 1 : On-orbit performance of the Gaia CCDs at L2}},
url = {{http://dx.doi.org/10.1051/0004-6361/201628990}},
doi = {{10.1051/0004-6361/201628990}},
volume = {{595}},
year = {{2016}},
}