The SWAP EUV Imaging Telescope. Part II: In-flight Performance and Calibration

Abstract

The Sun Watcher with Active Pixel System detector and Image Processing (SWAP) telescope was launched on 2 November 2009 onboard the ESA PROBA2 technological mission and has acquired images of the solar corona every one - two minutes for more than two years. The most important technological developments included in SWAP are a radiation-resistant CMOS-APS detector and a novel onboard data-prioritization scheme. Although such detectors have been used previously in space, they have never been used for long-term scientific observations on orbit. Thus SWAP requires a careful calibration to guarantee the science return of the instrument. Since launch we have regularly monitored the evolution of SWAP detector response in-flight to characterize both its performance and degradation over the course of the mission. These measurements are also used to reduce detector noise in calibrated images (by subtracting dark-current). Since accurate measurements of detector dark-current require large telescope off-points, we have also monitored straylight levels in the instrument to ensure that these calibration measurements are not contaminated by residual signal from the Sun. Here we present the results of these tests, and examine the variation of instrumental response and noise as a function of both time and temperature throughout the mission.

29 pages, 29 (colour) figures, 2 tables

References in corpus (3)

• The SWAP EUV Imaging Telescope Part I: Instrument Overview and Pre-Flight Testing
• Solar Coronal Structures and Stray Light in TRACE
• The First Stray Light Corrected EUV Images of Solar Coronal Holes

Cited by in corpus (40)

• The SWAP EUV Imaging Telescope Part I: Instrument Overview and Pre-Flight Testing
• Observations of an Eruptive Solar Flare in the Extended EUV Solar Corona
• On-Orbit Degradation of Solar Instruments
• Defining the Middle Corona
• Observations of the Formation, Development, and Structure of a Current Sheet in an Eruptive Solar Flare
• Observations of a Hybrid Double-Streamer/Pseudostreamer in the Solar Corona
• Study of EUV Emission and Properties of a Coronal Streamer from PROBA2/SWAP, Hinode/EIS and Mauna Loa Mk4 Observations
• Bridging EUV and white-light observations to inspect the initiation phase of a "two-stage" solar eruptive event
• Source Imaging of a Moving Type-IV Solar Radio Burst and its Role in Tracking Coronal Mass Ejection From the Inner to the Outer Corona
• First Perihelion of EUI on the Solar Orbiter mission
• SWAP Observations of Post-flare Giant Arches in the Long-Duration 14 October 2014 Solar Eruption
• Dynamics of Coronal Bright Points as seen by Sun Watcher using Active Pixel System detector and Image Processing (SWAP), Atmospheric Imaging Assembly AIA), and Helioseismic and Magnetic Imager (HMI)
• Multipoint study of successive coronal mass ejections driving moderate disturbances at 1 AU
• Density Fluctuations in a Polar Coronal Hole
• Structure and Dynamics of the 13/14 November 2012 Eclipse White-Light Corona
• Analysis of large deflections of prominence-CME events during the rising phase of solar cycle 24
• Moreton and EUV Waves Associated with an X1.0 Flare and CME Ejection
• Intense Flare-CME Event of the Year 2015: Propagation and Interaction Effects between Sun and Earth's Orbit
• Coronal Imaging with the Solar UltraViolet Imager
• Evolution of Coronal Cavity from Quiescent to Eruptive Phase in Association with Coronal Mass Ejection
• Predicting the COSIE-C Signal from the Outer Corona up to 3 Solar Radii
• Investigating Remote-sensing Techniques to Reveal Stealth Coronal Mass Ejections
• An Extreme Ultraviolet Wave Associated with A Solar Filament Activation
• Investigation of the Middle Corona with SWAP and a Data-Driven Non-Potential Coronal Magnetic Field Model
• Erupting filaments with large enclosing flux tubes as sources of high-mass 3-part CMEs, and erupting filaments in the absence of enclosing flux tubes as sources of low-mass unstructured CMEs
• Common origin of quasi-periodic pulsations in microwave and decimetric solar radio bursts
• First Simultaneous Views of the Axial and Lateral Perspectives of a Coronal Mass Ejection
• Automated Detection of Accelerating Solar Eruptions using Parabolic Hough Transform
• Three-Dimensional Reconstructions of Coronal Wave Surfaces Using a New Mask-Fitting Method
• Redefining the boundaries of interplanetary coronal mass ejections from observations at the ecliptic plane
• A new post-hoc flat field measurement method for the Solar X-ray and Extreme Ultraviolet Imager onboard the Fengyun-3E satellite
• The SWAP Filter: A Simple Azimuthally Varying Radial Filter for Wide-Field EUV Solar Images
• Assessment of the near-Sun magnetic field of the 10 March 2022 coronal mass ejection observed by Solar Orbiter
• Evidence of Extreme Ultraviolet Resonant Excitation in the Middle Corona During A Solar Flare
• Probing Velocity Dispersion inside CMEs in Inner Corona: New Insights on CME Initiation
• Initial radiometric calibration of the High-Resolution EUV Imager (${\text{HRI}}_{\text{EUV}}$) of the Extreme Ultraviolet Imager (EUI) instrument onboard Solar Orbiter
• Filament eruption with apparent reshuffle of endpoints
• Long-term Evolution of the Solar Corona Using PROBA2 Data
• LUCI onboard Lagrange, the Next Generation of EUV Space Weather Monitoring
• Observations of Ray-Like Structures in Large-Scale Coronal Dimmings Produced by Limb CMEs