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rgsenergy
July 2, 2008
Abstract
This task performs energy calibrations on RGS telemetry. The input dataset is
an event list created by rgsframes and is modied by the addition of the PI column
to the PIXELS table.
1 Instruments/Modes
Instrument Mode
RGS Spectroscopy
RGS High Time Resolution
2 Use
pipeline processing yes
interactive analysis yes
3 Description
This task calibrates the telemetered RGS pixel energies. It operates on a CCD-specic raw event list
created by task rgsframes and adds the PI column to the PIXELS table. The calibration consists of three
corrective procedures performed in sequence: oset correction, gain correction, and CTI correction. The
CAL Handbook describes each procedure in detail. The oset correction can use static calibration data
from the CCF (one value per CCD and node by each RGS), but also dynamic oset data derived from
the diagnostic images can be used for subtraction. There are two methods available:
 Using averaged diagnostic images derived from three consecutive orbits, including the one
corresponding to the data (parameter withdiagoffset). In this case the subtraction is
performed pixel by pixel. This is the method considered as most accurate, due to the oset
modulations observed with time within a CCD and node.
 Using any diagnostic data for derivation of one value per CCD and node (parameter withoffset).
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The method used for oset correction is agged in the keyword "OFFSCORR" in each EXPOSURE
extension of the events le (either as "CCDNODE" or "PIX2PIX", corresponding to the one value or
pixel by pixel subtraction, respectively).
For diagnostic purposes the gain and CTI corrections can be disabled independently (parameters withgain
and withcti).
Throughout this document a y marks items that do not apply to HTR mode data and a z marks items
that apply only to HTR mode data.
4 Parameters
This section documents the parameters recognized by this task (if any).
Parameter Mand Type Default Constraints
ccdset yes dataset events.ds
A CCD-specic event list from rgsframes.
withoset no boolean no
Enables override of the static energy oset calibration data, using a data le (parameter offset) such
as produced by task rgsosetcalc.
oset no dataset oset.ds
Energy oset calibration override data, enabled by parameter withoffset.
withdiagoset no boolean no
Performs the oset calibration by subtracting pixel by pixel oset values obtained from averaging di-
agnostic data over three consecutive orbits, including the one corresponding to the data. The average
diagnostic oset les (rrrr oooooooooo R[1][2]X000000OFX.FIT) have to be included in the ODF.
withgain no boolean yes
Enables gain correction.
withcti no boolean yes
Enables CTI correction.
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5 Errors
This section documents warnings and errors generated by this task (if any). Note that warnings and
errors can also be generated in the SAS infrastructure libraries, in which case they would not be docu-
mented here. Refer to the index of all errors and warnings available in the HTML version of the SAS
documentation.
6 Input Files
 ccdset
The following tables are required from the input dataset, which is expected to have been
created by rgsframes.
{ EXPOSURE
Required columns:
FRAME int32 frame identier
TIME real64 timestamp
{ PIXELS
Required attributes:
WINDOWX0 WINDOWY0 telemetry window: origin (node coordinates)
WINDOWDX WINDOWDY telemetry window: dimensions
RAWY z nominal readout row in HTR mode
Required columns:
FRAME int32 frame identier
RAWX RAWY y int16 coordinates
ENERGY int16 uncalibrated energy
CCDNODE int8 node identier
SHAPE y int8 shape code
GRADE y int8 number of pixels
 offset
CCF component containing RGS energy oset correction override data. See rgsosetcalc
for further details.
7 Output Files
 ccdset
The input dataset is modied by the addition of one column to the PIXELS table:
PI real32 calibrated energy
8 Algorithm
temporary column: TIME = EXPOSURE:FRAME[0]
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FOR EACH i,j such that (FRAME[i] == EXPOSURE:FRAME[j]):
TIME[i] = EXPOSURE:TIME[j]
new column: PI
IF (datamode == Spectroscopy):
PI = EnergyCorrector::offsetCorrect(TIME,RAWX,RAWY,SHAPE,CCDNODE,ENERGY)
ELSE:
PI = EnergyCorrector::offsetCorrect(TIME,RAWX,CCDNODE,ENERGY)
IF (*withgain):
PI = EnergyCorrector::gainCorrect(TIME,CCDNODE,PI)
IF (*withcti):
temporary column: SEP = 1000
IF (datamode == Spectroscopy):
PI = CtiCorrector::ctiCorrect(TIME,RAWX,RAWY,SHAPE,SEP,CCDNODE,PI)
ELSE:
PI = CtiCorrector::ctiCorrect(TIME,RAWX,RAWY,CCDNODE,PI)
9 Comments
References
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