EUI Data Release 5.0 2022-04
DOI: https://doi.org/10.24414/2qfw-tr95
"EUI Data Release 5.0 2022-04", released on 2022-04-28 contains the Solar Orbiter/EUI L1, L2 and L3 data for the period 2020-03-03 up till early April 2022. This release will continue to be appended with later incoming data, until the next full release (Release 6) is issued.
This data release contains the Solar Orbiter/EUI data from the Near Earth Commissioning Phase (NECP), the Cruise Phase and the first 3 months of the Nominal Science Phase, including all data from Remote Sensing Windows 1, 2 and 3. The NECP and Cruise Phase data contains numerous technical tests, for which the instrument configuration was often non-nominal. This data is therefore a-priori not suitable for scientific analysis but is instead primarily intended as a reference for the further development of analysis and visualisation software.
Data policy, citation & acknowledgements
The "EUI Data Release 5.0 2022-04" is public and can be freely downloaded from the EUI website and from the Solar Orbiter Archive. Publications using EUI data are asked to
- cite the EUI instrument paper "Rochus et al, AA, 2020" and the above DOI to identify which EUI Data Release was used
- mention in the acknowledgements "Solar Orbiter is a space mission of international collaboration between ESA and NASA, operated by ESA. The EUI instrument was built by CSL, IAS, MPS, MSSL/UCL, PMOD/WRC, ROB, LCF/IO with funding from the Belgian Federal Science Policy Office (BELSPO/PRODEX PEA C4000134088); the Centre National d’Etudes Spatiales (CNES); the UK Space Agency (UKSA); the Bundesministerium für Wirtschaft und Energie (BMWi) through the Deutsches Zentrum für Luft- und Raumfahrt (DLR); and the Swiss Space Office (SSO)."
- please inform david.berghmans@sidc.be (EUI Principal Investigator) of your work and/or publication, to facilitate cross-referencing and accumulate statistics for future reviews of the mission and instrument team. On request, the EUI team is happy to provide technical assistance during data handling. In return, co-authorship on eventual publications is expected.
- Specifically for data running up to the very first perihelion (March and April 2022), we ask external researchers to invite the core of the EUI team as co-authors on publications. Depending on the research topic and the availability of the EUI co-investigators , this could be up to about 20 co-investigators. In return, the external researchers can expect enthusiast support from the EUI co-investigators for any question concerning the handling of the EUI data. Please contact the PI david.berghmans@sidc.be to obtain the list of to be invited EUI co-investigators.
- The usage of EUI images as online web graphics or in printed materials should mention "Image Courtesy: ESA/Solar Orbiter/EUI".
List of changes as compared to EUI Data Release 4.0
- Data from 2020-03-03 till 2022-04-13 has been included. This release will continue to be appended with later incoming data, until the next full release (Release 6) is issued.
- The pointing information - the difference between the satellite and instrument boresights - has been updated in the in the EUI instrument kernels (SPICE kernels), based on measurements performed on February 12, 2022 data. This also includes a 0.1 degree difference in roll-angle for the HRI EUV telescope as compared to the previous releases (from -0.35 to -0.25 degree). The updated pointing information is applied to all files (both observation times both before and after February 2022). The only FITS files for which this pointing information is further updated (from L1 to L2 files), are FSI 174 and 304 L2 files for which the limb-fitting method converged.
- All L1 and L2 FITS files are internally compressed (tile-compression, RICE). For L1 files this procedure is lossless. For the L2 files the compression introduces a (small) quantization error, as the floating point data have been scaled between the minimum and maximum value in the data with 16-bit resolution. SSWIDL users should use "mreadfits_tilecomp" with the option "/use_shared_lib".
- Limb-fitting performance was significantly improved for all FSI images, resulting in improved pointing accuracy in FSI 174 and 304 L2 files.
- The calibration software (euiprep) has been updated at various locations without altering the functionality. Minor changes in the L2 files are possible.
- NaN values in L2 files no longer show up as bright lines in L3 files, but as dark lines instead.
- For GAINCOMB = 'both' images, the DOORPOS value that travelled down with the image has been corrected using housekeeping data. This fixes incorrect DOORINT and IMGTYPE for the affected images.
- For GAINCOMB = 'both' images, when making L3 files only the LG channel is used (the HG channel is ignored).
- The dark frame and flat field correction is now also applied for recoded images.
List of changes as compared to EUI Data Release 3.0
- Data from 2020-03-03 till 2021-09-15 has been included
- As compared to release 3, also additional data from the period 2021-02-20 till 2021-04-28 has been included. This was backup data that was received on ground after release 3 was created.
- Limb-fitting performance was improved for FSI 304 images resulting in improved pointing accuracy in FSI 304 L2 files.
- A bug occurred in Release 3 (flatfield not matching criteria) which implied that some HRI-EUV images on 2020-05-30 were erroneously removed. These files have been restored in Release 4.
- The calibration software (euiprep) has been updated at various locations without altering the functionality. Minor changes in the L2 files are possible.
List of changes as compared to EUI Data Release 2.0
- Data from 2020-03-03 till 2021-04-28 has been included
- FITS keyword IMGTYPE = 'occulted image' for FSI images with the internal door in occulting position (and external door open).
- For combined gain images, the FITS keyword COMP_RAT now gives the compression ratio with respect to a 15-bit raw image of the same dimensions (was 12-bit for all images).
- Improved matching of FITS keywords OBS_MODE, OBS_TYPE, OBS_ID to observations defined in SOOP kitchen.
- The FITS keywords SOLAR_P0, SOLAR_PE contained incorrect values in previous releases, this has been fixed.
- To improve the accuracy of the FITS keywords GAINHG, GAINLG, OFFSETHG, OFFSETLG, their values are now extracted from parameter table dump reports instead of from housekeeping data.
- The last 32 columns of the FSI detector have been systematically removed from L2 and L3 images as these columns are not functioning correctly.
- The calibration software (euiprep) has been updated at various locations without altering the functionality. Minor changes in the L2 files are possible.
List of changes as compared to EUI Data Release 1
- Data from 2020-11-01 till 2021-02-18 has been included
- L3 data is included
- Added FILCPOS keyword. This is the commanded filter wheel position (FILTPOS is the actual filter wheel position determined from service 5 messages)
- Fixed unknown internal door status (DOORPOS=255), DOORINT is now determined from service 5 messages.
- Fixed OBS_MODE and related keywords. Now correctly taking into account the modules defined in SOOP kitchen: EUV, LYA, FSI, COMMON_MODULE (so it excludes matches with flushes).
- Fixed OBS_MODE and related keywords. If images are outside of observation period as defined in SOOP kitchen, then closest observation period in time is found (as sometimes we are imaging slightly before an observation period, while those images belong to that same campaign).
- Fixed values of HEEX_OBS,HEEY_OBS,HEEZ_OBS, and GSEX_OBS,GSEY_OBS,GSEZ_OBS after mistake was corrected in SPICE kernels.
- Fixed FSI plate-scale in L1 (CDELT1 was incorrectly set to 4.43614 in previous release, it is now 4.4353411)
- The calibration software (euiprep) has been continuously updated at various locations without altering the functionality. Minor changes in the L2 files are possible. For this release, the git SHA (first 8 characters) is 64ce9853 (see also FITS header VERS_CAL keyword).
- Updated FILTER keyword for FSI files; the values Magnesium_304_n26, Zirconium_174_n25, Magnesium_304_n4, and Zirconium_174_n13 are now used to identify the four available filters. (blocking positions are still identified by the value blocked, and any other position has the keyword value undetermined.
Level 1 data
Level 1 data implies that the metadata in the FITS keywords is complete but that the images remain uncalibrated. Besides decompression, only limited, reversible operations have been applied to the images (mirroring & flipping, and 90-degree rotations) such that solar north is roughly on top and solar east roughly on the left. All the images received on the ground are distributed in the Level 1 dataset. This includes images with the telescope doors still closed, either "darks" or "LEDs" (calibration lamp images). The first of these were received on March 3, 2020.
This release contains 181874 L1 files.
Level 2 data
The euiprep python routine takes the Level 1 data and rectifies instrument deviations for which corrections are available. It also updates the WCS FITS keywords to correct for spacecraft pointing instabilities. The output of these calibration steps is distributed as Level 2 data. The euiprep routine is in an early development phase and in continuous evolution. The Level 2 data are thus a snapshot of the best available corrections at the time of the Level 2 data production.
The git version number of the euiprep S/W used to generate these L2 files is copied in the FITS header HISTORY keyword. For this release, the git SHA (first 8 characters) is (see also FITS header VERS_CAL keyword): - '9fd92712'
The euiprep routine is only applied to lossless compressed or uncompressed Level-1 solar images, starting with the 'first light' images on May 12, 2020. Technical images such as e.g. darks or LEDs are not processed into Level-2 data. The selection is done with the IMGTYPE keyword which is set to IMGTYPE="solar image" if * both the heat shield doors and instrument doors are open, AND * no LED is on AND * if the telescope has a filter wheel, that this filter is not in a blocking position.
For HRILYA, extra conditions are added to make sure the Screen and MCP voltages were properly configured for solar imaging. For HRILYA images with exposure time less or equal than 3s (XPOSURE LE 3.0) we require
LYACSCR > 3450 AND ((GAINCOMB="low-only" AND LYACMCP> 580) OR (GAINCOMB="high-only" AND LYACMCP> 450))
For HRILYA images with exposure time larger than 3s (XPOSURE GT 3.0) we require
LYACSCR > 3450 AND ((GAINCOMB="low-only" AND LYACMCP> 480) OR (GAINCOMB="high-only" AND LYACMCP> 350))
This release contains 175438 L2 files.
The L2 file version number is incremented every time the L2 file is updated and may thus differ from the L1 file version number.
Level 3 data
Level 3 data corresponds to a further processing of Level 2 data for visualisation purposes. The Level 3 image files are intended for visualisation through JHelioviewer. L2 images without the keyword WAVELNTH (e.g., because a wrong filter position was selected) are excluded from processing.
This release contains 175433 L3 files.
The L3 file version number is identical to the L2 file version number.
Known remaining issues
- Spacecraft pointing instabilities (thermoelastic, others) might affect the pointing metadata. It is recommended to use the pointing metadata only as a rough approximation. For FSI L2 images, the pointing metadata was updated using a solar limb-fitting procedure, and should typically be more accurate than 0.5 pixel for both FSI 174 and FSI 304 images, unless the solar limb is saturated in the image.
- CMOS sensor settings vary a lot throughout NECP. Various CMOS issues (image lag, unstable offset) are still being addressed at the time of writing. EUI images are not suitable for photometry yet.
- The calibration of the detector temperature sensor is to be improved. The temperature keywords (TEMPINT, TEMP1DET, TEMP2DET) can deviate.
- For HRILYA, LYCMCP and LYCSCR FITS keyword values are inaccurate for low values.
- HRILYA data taken on March 22, 2021 between 10:00:00 and 12:00:00 are incorrectly calibrated in L2/L3 (there is a sub-pixel misalignment between the lights and the applied darks/flats).
- HRIEUV combined gain images only have a column correction applied, not a gain correction. Furthermore, there is also a small LG and HG mismatch in the combined gain images.