Science Data
Contents
Science Data Processing
Data Releases and Data Rights
The mission implements a sophisticated multi-level data processing architecture. To reduce downlink requirements, part of the processing is performed onboard. The data then flows through a sequence of processing levels.
Science Data Processing
Data acquired in-flight by ARRAKIHS are provided to the Science Operation Center (SOC) and Instrument Operations and Science Data Center (IOSDC) for processing.
All data product levels are built sequentially, with each level depending on the products from the previous one. The processing levels are:
- Level 0: Raw telemetry and compressed science data received from the spacecraft, delivered to the Mission Operations Center (MOC).
- Level 1: Data decompression, formatting, metadata generation, and integrity verification performed by the SOC.
- Level 2: Instrument and detector calibration, photometric and astrometric corrections, and artifact removal performed by the IOSDC.
- Level 3: Co-added and combined science images at visit and target level.
- Level 4: Scientific catalogues generated from processed observations.
- Level 5: Specialized low-surface-brightness products optimized by removing foreground and background contamination to enhance studies of faint astronomical structures.
The processing pipeline includes corrections for detector non-linearity, dark current, flat-field effects, gain variations, cosmic rays, satellite trails, astrometric calibration, flux calibration, and sky-background characterization. Both visible (VIS) and near-infrared (NIR) instruments follow similar processing chains, although the NIR detectors require additional persistence corrections.
Data Releases and Data Rights
Releases will include all Level 1 to Level 5 data products. Each public release will be preceded by an internal release to the ARRAKIHS Mission Consortium to enable preparation of low surface brightness optimised Level 5 products. There will be three public releases:
- Data Release 1 (DR1): 3 galaxies, based on observations of galaxies that have been completed
in the first 6 months of the survey. - Data Release 2 (DR2): 25 galaxies, based on observations of galaxies that have been completed
in the first 18 months of the survey. - Data Release 3 (DR3): all ARRAKIHS survey targets (minimum of 80 galaxies).
Levels 1 to 4 data products for completed filler observations will be released to the Community at the time of scheduled Survey data releases. The releases will be made directly to the public with no prior or preferential access by the ARRAKIHS Mission Consortium for science exploitation before this time.
Early Release Observtions images will be released around the time of the In-orbit Commissioning Review, with the Level 1 to Level 3 data products following within a few weeks.
Selected data taken during Science Performance Verification Phase will be released, to include a fully reduced image of one of the ARRAKIHS Survey targets shortly after the end of the phase, and the Levels 1 to 4 data after 2 months. The Level 5 data will be included in DR1.
Releases to the Scientific Community will be via ESA ARRAKIHS mission webpages.