eSASS calibration database (CALDB)

The eSASS calibration database (CALDB) system stores and makes available files associated with the calibration of the eROSITA telescope. eSASS make use of the HEASARC CALDB framework to manage the eROSITA calibration files. To download the eSASS CALDB, please refer to this page. The eSASS setup script will handle automatically the access and the correct usage of the eSASS CALDB. To learn more about how a CALDB works, please visit the HEASARC CALDB site. In the following, the content of the eSASS CALDB is described.

Organisation of the eSASS CALDB

• eROSITA has 7 telescope modules (TMs), and each one has its own set of calibration files.
• The usual storage location of the eSASS CALDB is: /<my eSASS path>/caldb .
• The calibration files of the individual TMs reside in separate directories: /<my eSASS path>/caldb/data/erosita/tm[1-7]/bcf/.
• Star sensors BOKZ, SED1 and SED2 have their own sets of calibration files and their own directories: /<my eSASS path>/caldb/data/erosita/<starsensor>/bcf/.
• The gyro has its own set of calibration files in directory: /<my eSASS path>/caldb/data/erosita/gyro/bcf/.
• A new version of an individual calibration file is created each time this calibration data is updated. There are two exceptions: tm<id>_timeoff_190701v<??>.fits and tm<id>_badcamt_190701v<??>.fits. The version number of these files is only incremented if an already existing entry is changed, adding a new entry does not change the version number. This is because otherwise, the operational large number of new entries would drive the version numbers up.
• A calibration index file (caldb.indx), which exists for each TM, each star sensor and gyro, manages which calibration files are currently in use and for which period. For this, each calibration file is assigned a quality flag: from 0 for good to 5 for bad (-1 reason for bad flag unknown, -9 dataset no longer exists). Old calibration files are usually kept in the respective */bcf/ directory. The individual caldb.indx is located in the directory above */bcf/.

Naming convention of the calibration files

 
              <intrume>_<name>[_<detnam>][_<filter>]_<startvalidity>v<nn>.fits


       instrume		content of the INSTRUME keyword in cal file 
                        dummy calibration for testing, etc.: sim0, sim1, ...
                        eROSITA flight modules: fm1... fm7
                        eROSITA telescope modules: tm1... tm7
			
       name		type of calibration file from CCLS0001 keyword of cal file
       			e.g. 2dpsf for 2-dimensional point spread function.

       detnam, filter	if needed to distinguish between calibration datasets, 
       			optional keywords, may be used, e.g., to distinguish between
			several different filters used in one camera.

       startvalidity	validity start date from CVSD0001 keyword in the form 'yymmdd'

       nn		version number
      
      

List of calibration files for star sensors

Calibration file	Task using the calibration file	Description
bokz_boresight_170630v03	attprep	Boresight quaternion of star sensor BOKZ on ART-XC.
sed1_boresight_170630v03	attprep	Boresight quaternion of star sensor SED1 on eROSITA.
sed2_boresight_170630v03	attprep	Boresight quaternion of star sensor SED2 on eROSITA.

List of calibration files for gyro

Calibration file	Task using the calibration file	Description
gyro_boresight_170630v04	attprep	Boresight quaternion of gyro from 30.06.2017 on.
gyro_boresight_191131v07	attprep	Boresight quaternion of gyro from 30.11.2019 on.

List of calibration files for TMs

Calibration file	Version[1]	Task using the calibration file	Description
tm[1-7]_2dpsf_190220v03		erbox, ermldet, ersensmap, erbackmap, srctool	Survey-averaged and interpolated PANTER images; for data modelling (a detailed description you can find here).
tm[1-7]_2dpsf_190219v05		erbox, ermldet, ersensmap, erbackmap, srctool	2D PSF images interpolated from PANTER; used for PSF correction (a detailed description you can find here).
tm[1-7]_arf_filter_000101v02		expmap, srctool	Predicted and approximated ARF.
tm[1-4,6]_arf_open_000101v02		expmap, srctool	Only for TMs with on-chip filter.
tm[1-7]_avignet_010101v01			eROSITA vignetting coefficients.
tm[1-7]_avignet2_010101v01		Obsolete: was used by srctool, expmap	Analytic vignetting cofficients for vignetting computation.
tm[1-7]_badcamt_190701v<??>	-/-/01/-/-/01	evprep	Time intervals for which no or corrupt data exists. In Cal-PV only used for TM3 and TM6.
tm[1-7]_badpix_190712v<??>	-/01/-/-/-/01/01	expmap, srctool	Bright or flickering pixels or columns appearing after launch, used to account for lost area by bad pixels.
tm[1-7]_badpix_990101v<??>	01/-/01/01/01/-/-	expmap, srctool	Bright or flickering pixels or columns known before launch, used to account for lost area by bad pixels.
tm[4]_badpix_191205v02		expmap, srctool	New bright or flickering pixels or columns appearing during flight, used to account for lost area by bad pixels.
tm[1-7]_corr_algos_190701v	-/-/-/-/-/-	evprep	Time intervals for which special corrections have to be applied; they are not included in the standard pipeline processing; not used in Cal-PV data.
tm[1-7]_detmap_100602v02		srctool, evprep, expmap	Detector map; same as fovmap but data format is real.
tm[1-7]_energy_200130v03		energy	Parameters for the CTI and gain correction.
tm[1-7]_fovmap_190822v01		expmap	Detector map; same as detmap, but integer data.
tm[1-7]_instpar_190701v15	Fixed to 15.	apetool, evatt, expmap, srctool, tel, telatt	Detector geometry: focal length, platescale, number of pixels, boresight etc.; no information on time shifts which can be found in tm?_timeoff*
tm[1-5]_instpar_200212v<??[2]>	09/10-12/10/10-11/09-10	apetool, evatt, expmap, srctool, tel, telatt	Detector geometry: focal length, platescale, number of pixels, boresight etc.; with information on time shifts.
tm[6-7]_instpar_200213v<??[2]>	09/10	apetool, evatt, expmap, srctool, tel, telatt	Detector geometry: focal length, platescale, number of pixels, boresight etc.; with information on time shifts.
tm[1-7]_instpar_100705v<??[2]>	08/08/02/08/08/07/08	apetool, evatt, expmap, srctool, tel, telatt	Detector geometry with information on time shifts.
tm[1]_instpar_200331v10		apetool, evatt, expmap, srctool, tel, telatt	Detector geometry with information on time shifts for individual TMs.
tm[2]_instpar_191203v13		apetool, evatt, expmap, srctool, tel, telatt	Detector geometry with information on time shifts for individual TMs.
tm[3]_instpar_160523v09		apetool, evatt, expmap, srctool, tel, telatt	Detector geometry with information on time shifts for individual TMs.
tm[3]_instpar_200403v11		apetool, evatt, expmap, srctool, tel, telatt	Detector geometry with information on time shifts for individual TMs.
tm[3]_instpar_200509v12		apetool, evatt, expmap, srctool, tel, telatt	Detector geometry with information on time shifts for individual TMs.
tm[4]_instpar_191211v09		apetool, evatt, expmap, srctool, tel, telatt	Detector geometry with information on time shifts for individual TMs.
tm[5]_instpar_200506v11		apetool, evatt, expmap, srctool, tel, telatt	Detector geometry with information on time shifts for individual TMs.
tm[6]_instpar_200205v08		apetool, evatt, expmap, srctool, tel, telatt	Detector geometry with information on time shifts for individual TMs.
tm[6]_instpar_200213v09		apetool, evatt, expmap, srctool, tel, telatt	Detector geometry with information on time shifts for individual TMs.
tm[7]_instpar_200207v09		apetool, evatt, expmap, srctool, tel, telatt	Detector geometry with information on time shifts for individual TMs.
tm[1-7]_patfrac_140625v01		energy, srctool	Pattern fractions.
tm[1-7]_rmf_141103v01      tm[1-7]_rmf_141103v02		srctool	RMF derived from BESSY measurements.
tm[1-7]_slet_psf_181217v02		ermldet, shapelib	Shapelet PSF coefficients.
tm[1-7]_subpix_130101v01		energy	Parameters for the subpixel calculation.
tm[1-7]_thr_191001v01		evprep	Threshold maps used by evprep before version 2.21.
tm[1-7]_thrscal_200119v01		evprep	Scaled threshold map suitable for evprep-2.21.
tm[1-7]_timeoff_190701v01		evprep	Time and date of time shift by 1 sec; there are only shifts between 0<->+1.
tm[1-7]_tvignet_100302v01		apetool	Total (mirror+obscuration) vignetting function.

[1] If different for individual TMs in Cal-PV processing .

[2] Version number is always lower than 15.