Data packages have been delivered for period P87 (April-September 2011) and before.
For new data, acquired after the begin of October 2011, data packages are no longer
created. Users can access their raw data in electronic form through the ESO User Portal.
Data for VLT pre-imaging runs are processed and delivered as
For completeness, the structure of the historical packagesis described
Science data have been processed by the pipelines with the best available calibration data. Please note that ESO is not assuming any responsibility in respect to the usefulness of the reduced data. The adopted reduction strategy may not be suitable for the scientific purpose of the observations.
|top PACKAGE DIRECTORY STRUCTURE
The top-level structure of the data package is as follows:
For each observation block (OB) that has been executed on Paranal, you find all measured raw data (FITS files) in a directory named by the OB number (FITS key HIERARCH.ESO.OBS.ID). If pipeline products exist, these are also added in the OB directory.
The GEN_CALIB directory collects all those calibration files (raw and products) that have been measured as part of the regular calibration plan, and calibration frames of a general nature (like static line tables). The GEN_INFO directory has general information, like data reports and night logs.
The tree shown above is the logical structure, which means that this is the way the data have been organized before they have been put onto media. Depending on the size of your package, the directories may be distributed across several media. It is a good idea to create the original tree on your local disk and then copy all files from the media into this tree.
<OBS_ID> (e.g. 179211)
For each executed observation block of your run, the package contains a directory with all measured data from that OB. All data under <OBS_ID> carry your run ID.
Note that some of your OBs may have been executed more than once. In particular, if time permitted, observatory staff try to re-execute OBs which produced data clearly out of the specified constraints. Check out the NIGHTLOG.html file for details (go to "OB information"). All data from OBs that have been executed multiple times are found in the same directory.
Each OB directory is further subdivided into subdirectories for science frames, calibration frames, and log files. In many cases, there will be science data only, but there may also be OBs with attached calibration data:
All acquisition frames (DPR.CATG=ACQUISITION) from the OB are contained in this directory. This directory only exists if such data exist.
All raw science frames (DPR.CATG=SCIENCE) from the OB are contained in this directory.
Here you find the pipeline-processed science data. The naming scheme can be found here.
If measured, raw calibration frames (DPR.CATG=CALIB) produced by the OB are contained in this directory ("attached calibrations"). These are the ones which have been taken upon user's request in addition to the ones from the calibration plan.
Calibrations measured as part of the regular calibration plan are stored under the GEN_CALIB directory.
The pipeline products of the raw attached calibrations are delivered here.
The CALIB products are renamed. The naming scheme can be found here.
This directory holds logging information about processing and packing
of your data:
- Association Blocks (.ab)
- association logs (.alog)
- logs of the pipeline processing (extension .rblog)
- scoring results (.html) (optional)
- extraction from the nightlog, OB grade, QC0 report (.qcm)
- a reduction comment (.cmt) (optional)
- Association Blocks (ABs) are text files which contain all the
information required to pipeline-process and pack data. This information includes
the reduction recipe, the input raw file(s), the calibration products needed
for processing, and the names of the final products. More ...
- Association logs are delivered since P80. They are a simplified version of ABs, designed to provide the association information essential for the user. More ...
- The pipeline processing log is a record of the science reduction process, with a detailed log of reduction steps, results etc.
- The scoring report is intended to give some feedback
about the data quality. It is still experimental. More ...
- The nightlog file is an extracted version (per OB) of the summary
qc0 report and the NIGHTLOG.html file (see below). More ...
That directory in addition holds QC plots, if available.
This directory collects all calibration frames from the regular calibration plan that are associated to your science data. It also contains their pipeline products, and calibration frames of a general nature (like static line tables). Calibrations that have been measured by user-defined OBs and that have been used for pipeline processing of science data may be included here in addition.
The directory has four subdirectories (gen, logs, proc, raw), two of which have further fine-structure:
Raw calibration files. These divide into raw file types (e.g. BIAS, FLAT etc.; see instrument specific section below).
Calibration products derived from the raw calibrations. These divide into file types like the raw calibration files, see instrument specific section below.
The CALIB products are renamed. The naming scheme can be found here.
Association Blocks, association logs and processing logs for the
calibration files under GEN_CALIB. There might also be scoring logs (.html files).
General calibration data of static nature.
Additional or missing raw calibration files may be retrieved anytime from the generic
ESO Archive form, or from the instrument specific forms.
Calibration data are public immediately while SCIENCE data normally have a proprietary period of one year.
This directory hosts some general information. It has the following subdirectories:
||nightlogs, OB report (HTML files), association report
||executable scripts (presently one: print_all_reports)
The data package contains the following report files:
||the package portal page: point your browser here to find all information
||a table describing the naming scheme for product files
||list of all proprietary files (SCIENCE, attached CALIBs) as read from the archive
||list of all SCIENCE files, containing the comparison between the user constraint set and the actual values
||set of html files with nightlog, OB and association information
|summary report of the fits files in each directory (these files are provided in text [*.txt] and PostScript format)
||all data directories
The executable script print_all_reports under GEN_INFO/scripts can be used to print all postscript files in your package.
Archive report: archive_<RUN_ID>
While the above listings are about files in the package, the archive report is the result of a query to the ESO Archive. It is useful as a check on the completeness of the data package. All files created by OBs which have been generated by the PI are listed here. The list includes all SCIENCE files, and the attached calibrations, and acquisitions, if applicable.
QC0 report: qc0_<RUN_ID>
This report is sent only for Service Mode runs.
This file contains a report of quality control parameters ('QC level 0' where level 0 stands for Quality Control without pipeline processing) for your raw SCIENCE files. These parameters are airmass, seeing, moon distance, and fractional lunar illumination. They have been measured on site (column 'msrd'). They are compared to the required values as defined in your OBs ('targt') and flagged (OK/NOK).
The list is intended to give a rough indication of whether or not the required constraints have been fulfilled. They should not be interpreted in a too formal way, however. E.g., there may be cases where the seeing was worse than required, but this was compensated by a longer exposure time. Check the night reports for details.
Note that the seeing values reported here are DIMM seeing values, they are not measured on the frame. If the alarm flag ("NOK") is set in the SEEING column, the DIMM seeing value was larger than your seeing constraint during the indicated obseration. However, in many cases, the delivered seeing in the instrument focal plane is better than the DIMM seeing. Whenever possible, the on-site astronomer has measured the focal plane immediately after or during execution to determine the success or failure of your observation. Thus, your observation may have been completed within your specifications, even if the SEEING alarm flag is set. Please review the affected observation carefully and check the night reports for details.
sample file (.txt)
Night logs, OB logs and Association report
This is a set of HTML files with night log information, OB grading information and data association information. All relevant information about the nights contained in your package is included here, as well as information about each OB in your delivery.
Point your browser to GEN_INFO/ObservingReports/NIGHTLOG.html (or start from the package portal page, README.html) and navigate per night (labeled as 1), per OB (2) or per set of files (3).
The HTML files also come as stripped-down, printer-friendly versions. The files are organized to have a summary on top, and details below.
You can use either the navigation bar to jump to a specific night/OB/set of files, or use the up/down arrows (night logs only) to browse sequentially. The OB navigation bar (2) uses colour coding to give you a quick impression about OB grading. There are additional links to ambient condition information.
The association report (3) organizes your data and their association. It has two main levels: the OB (observing block), and the AB (association block) which collects raw file(s) and associated information like product files, calibration files, log files etc. This report gives you an impression how the data in your package are logically linked, while the listings in each directory give you a table of contents. File names in the association report may show up several times, e.g when a calibration file has been used for processing more than one science file.
- The external links (like the ASM links: seeing, sky transparency etc.) will only work with network connection.
- The ASM links require java-enabled browsers.
- The navigation bars read best with style-sheets and java-enabled browsers.
|Sample nightlog files
Known IRAF problems
- Filename Length. To display or manipulate the FITS files
with older versions of IRAF (before 2.11), you can:
- copy these FITS files to your hard-disk and rename them with filenames <= 32
characters in length;
- create symbolic links with filenames <= 32 characters in length to your DVD
- Header Interpretation. ESO FITS files use the ESO HIERARCH FITS keyword extensions standard to all ESO telescopes. Note that IRAF treats all ESO HIERARCH header lines as COMMENT lines, i.e. IRAF and IDL cannot automatically interpret the information provided in ESO HIERARCH header lines. The problem may be solved using the tool hierarch28. Find information about this tool here.
- RA, DEC. Please note that the RA and DEC keywords are recorded in degrees. To translate these keywords so that they can be used by IRAF you have to use the asthedit task in the noao.astutil package. The help file for this task gives an example of how to translate the ESO format to the IRAF format.
Stand-alone FITS handling tools
Find information about FITS header handling tools (e.g. dfits, fitsort, hierarch28) here.
For further information about FORS2 data and QC have a look at:
|top FORS2 CALIBRATION PRODUCTS
Appropriate calibration data (these may be raw and/or processed [master]
calibration data) are always delivered.
Master calibration data, if available, are delivered according to the
instrument mode of the science raw data. Their names
contain information about their function and instrumental modes.
The following master calibration data are in general included:
bias frames under BIAS,
twilight sky flats (IMG) under FLAT,
reduced photometric standard star exposures and zeropoint tables (IMG) under STD,
normalized screen flats (LSS, MOS, MXU) under LAMP,
wavelength calibration files (LSS, MOS, MXU) under LAMP,
files to correct spatial distortion (MOS, MXU) under LAMP,
reduced spectroscopic standard star spectra (LSS/MOS) under STD.
For IPOL and PMOS modes, only raw polarimetric calibration data are delivered.
|top FORS2 SCIENCE PRODUCTS
If you have measured in the IMG, LSS, MOS or MXU mode, you can expect to receive
pipeline-reduced files if they fulfil the following conditions:
they are measured in supported (standard) modes
master calibration data were available from the same night or at least
within a few nights
PROBLEMS, ISSUES, HINTS
Problems may also be related to the pipeline processing or may result from features of the instrument.
data included for IMG mode
For imaging projects, photometric standards are observed on every clear
night through the filters being used that night. Clear nights are defined
as nights when no clouds are visible. However, we can not certify these
nights as photometric.
are included in the calib directories. These should allow you
to establish the photometric zeropoints for that night, as well as extinction
and colour coefficient if sufficient data exist. Extracted fluxes of the
standard stars (tables PZPI) are intended only for quality control and should not be directly used to derive photometric
the raw standard star files (DPR CATG = STD)
the reduced standard star files (PRO CATG = REDUCED_STANDARD_IMG)
Pipeline-generated zeropoints per night are obtained by averaging all
available standard star measurements. Again these are intended only for quality control purposes and not for scientific information (find more information here).
NOTE: some of the
STANDARD star files (raw or reduced) may contain saturated pixels. So check
them carefully if you want to use them. Pipeline-produced zeropoints are
checked for overexposure.
MXU: Wrong number of slitlet keywords for CALIB data
MXU calibration frames can inherit slitlet information from calibration frames taken before for another MXU setup. If the previous setup has more slitlets than the current one, the information for the current setup is correctly written, but the surplus keywords are not deleted. Therefore the header will show a setup with too many slitlets.
Example: The current setup has 45 slitlets, whereas the previously observed setup had 70 slitlets. Then the first 45 slitlet keywords carry the correct information for the current setup, whereas the slit keywords 46 to 70 still have the information from the previous setup.
This problem does not occur for SCIENCE data and has been solved by November 13, 2006.
FORS2 LSS science observations: only 1 chip of spectrophotometric standard star observations associated
During the time August 2005 to Jan 19, 2006 we did not pack both CCD chips of the appropriate spectrophotometric standard star observation (STD_MOS), but only the one closest in time to the respective LSS science observations. Usually this was chip 1, which again usually contains the spectrum of the spectrophotometric standard. If you received instead spectrophotometric standard star observations without a spectrum you can retrieve the missing data from the archive.
LSS science observations: wrong CALIB associated
During the time July to December 2005 some LSS science data had wrong CALIB data (wavelength calibration and/or flat fields with slit widths different from those of the science data) associated to them. Correct CALIB data can be obtained from the archive for FORS1 and FORS2. PIs of affected programs have been notified.