HV_POWER T
HV_ENBL T
RUNNING_MODE T
CELL_HIGH_VOLTAGE -20200.0,-19800
PMT_HIGH_VOLTAGE 1090.0,1120.0
EARTH_ANG 4.0,INDEF
These defaults settings can be modified by the user.
This generates a fits file with GTI
(e.g. fot_000232_LE_01_gti00.fits) which can then be applied in XSELECT.
lecspipe is divided in four stages which can be run independently:
--------------------------------------------------------------------------
STAGE I : Event Files Concatenation, HK data conversion & gain computation
--------------------------------------------------------------------------
------------------------------------------------
STAGE II : events correction
------------------------------------------------
------------------------------------------------
STAGE III : events selection and GTI creation
------------------------------------------------
----------------------------------------------------------
STAGE IV : accumulation of final products (using XSELECT)
----------------------------------------------------------
To run, for example, stages II and III only type:
lecspipe datadir=./ baryconv=no entrystage=2 exitstage=3
Plotting of
housekeeping data, ratemeters,
attitude data,and
ephemeridis data, and
selection based on these plots, can be performed
interactively
using the program hkplot
A number of housekeeping parameters and ratemeters should be checked
routinely:
| E_MIN_RATEMETER | counts above lower energy threshold |
| E_MAX_RATEMETER | counts above higher energy threshold |
| PHA1 | centroid of cal. source 1 |
| PHA2 | centroid of cal. source 2 |
| GAIN_AVG | Average gain |
| RA_SCZ | RA Z axis |
| DEC_SCZ | DEC Z axis |
| ROLL_AN | Roll angle |
| EARTH_ANG | Elevation angle |
| BREARTH_ANG | Bright Earth angle |
| SUN_ANG | Sun angle |
| COR_MIN | Geomagnetic cut-off rigidity |
MECS WALK THROUGH
Go into the directory containing the FITS files.
The operations of concatenation, correction and screening
can be performed automatically
by using the script saxpipe, which
will run in sequence the programs that perform each single operations.
Each program can of course be run independently. saxpipe instr=ME
will run the programs for each MECS unit, in the following example
we use MECS 1.
saxpipe instr=ME indir=./raw outdir=./clean
Find the observations with the same experiment configuration and
concatenate them:
Executing command: mksaxobs
instr=ME indir=test outdir=clean slewobs=no
mksaxobs executes the following command:
Executing command: meselobs ins=ME filelist=clean/32243.ls active=none | mecatobs
filelist=stdin outdir=clean stem=-
Conversion of housekeeping data from digital to physical units:
Executing command: meeng2phys
infile=clean/fot_000491_M1_01_rhk.fits outdir=clean
Accumulation of calibration source spectra as a function of the time,
fit of the centroids and storing of the fit results in the
hosekeeping data:
Executing command: mecalcgain
infile=clean/fot_000491_M1_01_rev.fits plotspec=0,1
Event correction and data screening.
We can perform the following corrections:
spatial gain correction
temporal gain correction
linearization
dead time correction (to be implemented)
conversion from detector to sky coordinates
barycentric correction (to be implemented)
And the following screenings:
Removal of events detected outside the detector window
selections of events in a given burstlenght interval
All operations are executed by the program
meevelin
Executing command: meevelin
meevelin infiles=fot_000491_M1_01_rev.fits indirpath=clean rmevents=yes blsel=yes tgain=yes sgain=yes lincrd=yes sky=yes
Data selection.
We reject data from periods of high backgroud and then select
Good Time Intervals.
Executing: memkgti
hkgfile=./fot_000491_M1_01_hkg.fits stdhkints=yes verbosity=3
Executing: maketime infile=clean/fot_000491_M1_01_hkg.fits+2 outfile=clean/fot_000491_M1_01_gti00_2.fits expr='GAIN_AVG.GT.0.5 && GAIN_AVG.LT.1.5 && FOV_FLAG==0 && BREARTH_ANG>=5.0 && EARTH_ANG>=5.0 && !SAA_FLAG && COR_MIN>=6.0 && SUN_ANG>=60.0' name="" value="" time=TIME compact=no
Periods of Earth occultation can be identified using
attitude and ephemeridis data. Data selection is then performed
accepting data in intervals of the following quantities:
GAIN_AVG 0.5,1.5
SAA_FLAG F
FOV_FLAG 0
EARTH_ANG 5.0,INDEF
BREARTH_ANG 5.0,INDEF
SUN_ANG 60.0,INDEF
COR_MIN 6.0,INDEF
These defaults settings can be modified by the user.
This generates a fits file with GTI
(e.g. fot_000491_M1_01_gti00.fits) which is then applied by
fltime or that can be applied in XSELECT.
Executing command: fltime infile=clean/fot_000491_M1_01_lev.fits+2 gtifile=clean/fot_000491_M1_01_gti00.fits outfile=clean/fot_000491_M1_01_lev_flt.fits column=TIME copyall=yes
This has generated a filtered and linearized event file
fot_000491_M3_01_lev_flt.fits.
saxspipe instr=ME is divided in four stages which can be run
independently:
------------------------------------------------
STAGE I : Event Files Concatenation
------------------------------------------------
------------------------------------------------
STAGE II : HK data conversion & gain computation
------------------------------------------------
------------------------------------------------
STAGE III : events correction
------------------------------------------------
------------------------------------------------
STAGE IV : events selection and GTI creation
------------------------------------------------
To run, for example, stages II and III only type:
saxpipe proddir=clean entrystage=2 exitstage=3
Plotting of
housekeeping data,
attitude data,
ephemeridis data and
ratemeters , and data
selection based on these plots, can be performed
interactively
using the program hkplot
A number of housekeeping parameters and ratemeters should be checked
routinely:
| VALEMIN (or CSELO) | counts above lower energy threshold |
| REJEMAX | counts above higher energy threshold |
| PHA1 | centroid of cal. source 1 |
| PHA2 | centroid of cal. source 2 |
| GAIN_AVG | Average gain |
| RA_SCZ | RA Z axis |
| DEC_SCZ | DEC Z axis |
| ROLL_AN | Roll angle |
| EARTH_ANG | Elevation angle |
| BREARTH_ANG | Bright Earth angle |
| SUN_ANG | Sun angle |
| COR_MIN | Geomagnetic cut-off rigidity |
| | Geomagnetic cut-off rigidity |
Final producs extraction.
saxpipe, lecspipe or the interactive analysis have generated a
cleaned and corrected event file
(eg. fot_000491_M1_01_lev.fits) which
can then by processed by XSELECT to extract images, spectra and
light curves. It is of course possible to perform further
data selections with XSELECT before the final products accumulation.
At this point the observer should be ready for
the scientific analysis of SAX LECS and MECS data.
Questions, comments or suggestions concerning the SAXDAS software
can be addressed
to
helpdesk@sax.sdc.asi.it
This page is maintained by
Fabrizio Fiore