Data of programs performed in Service Mode are distributed on DVDs, in case the program is larger than 1.3 Gbyte (=2 CDs), or CDs. Details on the data shipping can be found on the archive web page . A description of how to read optical media produced by the ESO/ST-ECF archive can be found here.
PLEASE NOTE that on 2004 May 14 a new NACO detector was installed.
Assume your VLT run ID is 70.H-0447(A) and you obtained data on 2001-04-25 and 2001-06-08. Assume furthermore that your VLT data were measured in a pipeline-supported mode. You will then find your data (as FITS files) organized in the following way:
If your data have not been pipeline processed,
the structure will be:
Remember this tree is the logical tree, i.e. this is the way the data have been organized before they have been put onto CDs/DVDs. Due to the 600MB capacity of the CDs, it may well be true that some of these directories have been chopped onto two CDs. It is a good idea to create this tree on your local directory and then copy all files from CDs into this tree.
|CONTENT OF DIRECTORIES|
|Raw data summary file: list_of_all_obs|
This file gives a short description of each FITS file on this disk. This information has been extracted directly from the FITS header.
text file prints well with UNIX a2ps if tuned to landscape format, font
size 5.0 .
|Calibration data summary file: list_of_all_calibs|
A similar file is provided for the raw calibration frames:
|Reduced data summary file: list_of_all_red|
A similar file is provided for the reduced science and reduced calibration frames
Science products and master calibration
data follow the NACO naming convention.
|QC0 summary file: <RUN.ID>_qc0_report.txt|
This file < run_id > contains a report of quality control parameters ('QC level 0' where level 0 stands for QC 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 obeyed. 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 frames
or on the jitter products.
In P70, no qc0 reports are included in NACO Service Mode packages.
|QC1 summary file <RUN.ID>_qc1_report.txt|
Science Raw Data
We deliver all the FITS files produced by Observation Blocks you created and that we were able to execute. Note that some of your OBs may have been executed more than once. In particular, if time permitted, we tried to re-execute OBs which produced data clearly out of the specified constraints.
We are also sending you all available calibration data appropriate for your program. These data may include:
ESO is further making an attempt to provide master
calibration frames which have been produced by the quality control group. Some
of these files may be included in your data set and are marked accordingly. They
are stored in the reduced/ subdirectories of each
Not all programs will receive all classes of calibration data.
TWILIGHTFLAT frames in different filters are included when available.
observations as taken by the observatory as part of the VLT NACO calibration plan
to monitor the photometric zeropoints are included for those nights for which
science frames have been for collected for the current OBS.PROG.ID.
For more information about the quality control (QC) procedures and results of NACO calibration data, check the NACO QC pages.
Whenever possible we included reduced data, i.e. master calibration frames and/or combined jittered images/spectra produced by the pipeline 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.
Quality checks for both the
production of master calibrations and for science reduction are applied
|PROBLEMS, ISSUES, HINTS|
Fits header extensions
Note that NACO science fits files consist of three parts, the main file and two image extensions. The usual way to specify an indiviudual extension is to append the '[<n>]' to the file name (e.g. NACO.2003-01-01T12:13:14.123.fits). ESO-MIDAS (from Version Sep02 on) users will use commands like 'help [Filename]' and 'indisk/mfits' to handle NACO fits frames or display it via 'load/ima NACO.<timestamp>.fits'. eclipse users do not have to handle the extensions separately. iraf users will use 'display NACO.<timestamp>.fits' when using SAOimage. The RTD and SkyCat can be called with the normal filename 'rtd -file NACO.<timestamp>.fits' and all extensions are shown in a separate pop-up.
Vignetting has been found for objectives S54, S27 and S13. About 80 pixels of the lowermost lines are vignetted by S54 and about the 40 lowermost rows for S27. For S13 only a few rows are vignetted. There occurs also a vignetting at the left rim (about the 5 most left columns). To improve the shift-and-add algorithm used by the jitter recipe it is usefull to ommit the vignetted part completely instead of mixing real background and fake background (= obscured parts). We will overwrite the initial RejectBottom = 100 key in the default jitter ini file. (WH 2002-11-21)
The headers of the extensions of NACO science fits frames are corrupt. The keys GCOUNT and PCOUNT are missing. The missing keys have no impact on the current scheme of data processing, since the extensions, containing AO-related information is not used by the pipeline. The main frame can be processed by MIDAS and all three frames can be displayed by RTD/SkyCat.
The twflat recipe must handle stacks with alternating readout modes, in particular when corresponding darks are submitted to the recipe as part of the calibration cascade. In P70, tw/sk flat calibration products have been generated without submitting a dark. The recipe hence produced an interception map, which is the A in the linear fit: Flat=A+Bx. As a coinsequence the error bars for the slope became rather large, in case the flux range was not large enough in the raw frame stack. From P71 on master tw/sky flats are generated using the twflat recipe and using the -d <darklist> option. Interception maps are no longer provided.
On August 13-16, 2003 there was intervention on CONICA. As a result, the S27 and L27 FOV are now free of vignetting. The S54 has very small vignetting (28 rows on the bottom of frame) and the L54 has some vignetting on the right hand side. The dark current was lowered. However, electrical interference in the form of horizontal lines was noticed for the first time. They are occasionally seen in the post-intervention data and their occurrence seems to be random. Also, the 8-pixel noise has returned. It had been removed during the intervention that took place on the detector last year but is back now. Due to these high frequency variations the Read-Out-Noise (RON) values increased in case of every read-out-mode (where Double_RdRsRd appears to be affected most). For reference see NACO trending plots and control charts . It appears to have uncorrectable random pattern but shows decreasing trend with time. Special routines are developed to monitor it closely.
It has been found that the dark frames are different depending on camera used in the instrument configuration. To take this effect into account operational change was implemented. Since November 05, 2004 the calibration darks are taken to match the camera the science data were taken with.
Known IRAF Problems
Filename Length Problem: To display or manipulate the FITS files with older versions of IRAF (before 2.11), you can:
Header Interpretation Problem: 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.
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.
ST-EFC Science Archive Facility provides a stand-alone hierarch28 fits tool which does the FITS header conversion.