SUMER Emblem SUMER Data Availability

The instrument SUMER produces spectral images in the Solar UV. The basic form of SUMER data is a two-dimensional detector image: one dimension being the (usually north-south) spatial extension of the slit, the other dimension being spectral, i.e. a wavelength interval.

detector

On-board, this detector image (or subsets thereof) can be aggregated and/or compressed. The result is sent down (compare Telemetry Format Table under "spectrohelio1" description in our Operations Guide), together with a descriptional header, containing information such as: when the image was taken, where the telescope was pointed, which detector was exposed and how long, which wavelength was situated where on the detector, which slit and raster step was used, etc. (Notice on coordinates!)

These telemetry data are put on CD-ROMs by NASA, and they are also put together as FITS files in the EOF (cf. comments by Nicolas Morisset). These FITS files contain an additional descriptive header, including information from the planning process. But even with this and the use of SUMER publications, it may be hard to work with SUMER data all by oneself; for this reason the involvement of SUMER Co-Investigators is strongly encouraged.

Digital Data

The easiest way to get access to SUMER data is to work with our teams at Max-Planck-Institut für Sonnensystemforschung (MPS) in Germany, at Institut d'Astrophysique Spatiale (IAS) in France, or at NASA's Goddard Space Flight Center (GSFC). With an account on the teams' workstations, you have direct access to (decompressed) FITS file data (at IAS and GSFC), or to (still compressed) telemetry data from CD-ROMs (at MPS).

For most of the time, the SUMER team was not funded to make data available to the general public, instead we have made the data available to ESA/NASA for this activity. Their SOHO Main Catalogue includes SUMER FITS files and a search facility. - Since May 2001, the MPS computer centre has set up a web-based system (SUMER Image Database) which allows to browse through and download SUMER images. Policies concerning access to SUMER data are stated below.

Summary Data

Each day, when SUMER is operating, a number of studies are run, resulting in a vast number of spectral images as described above. A day-by-day catalogue has been set up, allowing users to browse through the study names and starting times. Links are provided to related information extracted from the FITS files' headers, including study number, detector, Solar coordinates, exposure time, wavelength range, and target (if any).

Graphical Data

For a limited number of studies, there are verbal descriptions and pictures in the SUMER Gallery. These include links to downloadable Postscript or GIF files of standardized images, and a few animations (as IDL routines). The descriptions sometimes have information on who initiated the study and will probably publish the results, on what was done with SUMER and possibly might be done in the future. (And maybe it rises interest about what could be done with the existing data.) Pictures include intensity, line shift, and line width displays, as well as spectra. - Some of our pictures can also be found in the SOHO Summary Database.

The SUMER Gallery will grow as more and more data is analyzed. Together with the instrument's description, it is the closest we have to something that can be termed "educational" ... but then you can always visit SOHO Explore.

Other Levels

The SUMER team is determined to keep up-to-date the raw data and the software to extract and process it. The SUMER team does not intend to distribute other levels of data. For example, no one should be forced to use our calibration routines; the calibration of SUMER data is a continuing scientific process, and we do not want to be held responsible for different versions of data due to calibration changes.

The goal of our data access policy during the first years of operation was: The Principal Investigator, Klaus Wilhelm (MPAe), has the final word and acts together with Philippe Lemaire (IAS) as arbiter in case of disputes. All SUMER data will be in the public domain one year after they have been received. At that stage the responsibility of any use rests with the user. The SUMER team would still be interested in a continued coordination scheme, but the initiative must come from the user. It is, however, expected that SUMER will be acknowledged as data source in all publications resulting from SUMER observations.

SUMER Data Access Policy

WHO                 ACCESS TO                        LIMITATIONS
---                 ---------                        -----------

PI and              Full SUMER data set;             Subject to data analysis
CoIs                protect exclusive rights         coordination scheme;
                    defined below                    inform PI

Associated          Full SUMER data set after 9      Subject to data analysis
Scientists          months; protect exclusive        coordination scheme;
                    rights defined below             inform PI
Specific            Limited data set related         At least one CoI must be
Observations:       to their specific involvement    involved and co-author
                                                     of publications

'Official guest'    Limited data set (POP/JOP/UDP    At least one CoI should be
investigators       or other observations) in which  involved, or more if
(at least one CoI   they are involved, exclusive     the objectives and
involved guiding    right on this set until data     observations demand this
the investigation)  will go to public domain

'Inofficial guest'  Limited data set (POP/JOP/UDP    At least one CoI must be
investigators       or other observations) in which  involved, or more if
(at least one CoI   they are involved, exclusive     the objectives and
involved guiding    right on this set until data     observations demand this
the investigation)  will go to public domain

Change in policy

The policy defined above was successfully applied until 26 April 2000. From then onwards, the SUMER data will be in the public domain as soon as they become available.

The SUMER team would continue to be interested in coordinating the data evaluation effort along the lines outlined above. At the very least, we would expect to be informed of any resulting publication.

Information may also be found in the Space Physics Data Availability Catalog.

IED 22 May 2001

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