Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://xmm.vilspa.esa.es/docs/documents/CAL-TN-0014-1-0.ps.gz Äàòà èçìåíåíèÿ: Thu Jan 11 19:29:40 2001 Äàòà èíäåêñèðîâàíèÿ: Mon Oct 1 21:16:38 2012 Êîäèðîâêà: Ïîèñêîâûå ñëîâà: mars odyssey

Evaluation of Tests of SIAM version 7 during Revolution 185
XMM­CAL­TN­??
C. Erd, D. Lumb, R. Much
December 15, 2000
1 Introduction
We compared the pointings with the SIAM v7 with those of previous observations which were using
SIAM v5.
In the following we use rotations around spacecraft axis (R y , R z ) for the specification of shifts.
All differences are given as rotations of the spacecraft starting from a pointing derived by using
SIAM v5 and then rotating by R y and/or R z such that the current position is derived.
R y ? 0 =) shift of detectors to Z ! 0 =) shift of source in image to Z ? 0
R z ? 0 =) shift of detectors to Y ? 0 =) shift of source in image to Y ! 0
2 Measurements
The X­ray instruments used the observations of AB Dor, while for the OM BPM 16274 was used
(two observations).
The results of the measured shiifts are given in Tables 1 & 2.
Instrument R y R z
(arcsec) (arcsec)
EMOS 27 \Gamma75
EPN 28 \Gamma80
RGS 28 \Gamma84
OM 20 \Gamma74
Table 1: Measurements of apparent satellite rotations from pointing with SIAM v5 to pointing with
SIAM v7.
It is not understood why the R z of the MOS and R y for OM are systematically outside the
remainder of the measurements.
These measurements are consistent within a few arcses with the input that went into the gener­
ation of this SIAM matrix, which is given here for completeness:
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Instrument R y R z
(arcsec) (arcsec)
EMOS 59 \Gamma7
EPN 58 \Gamma12
RGS 64 \Gamma13
OM 56 \Gamma10
Table 2: Measurements of apparent satellite rotations from pointing with SIAM v5 to pointing with
SIAM v7. Prime instrument was RGS.
Prime R y R z
Instrument (arcsec) (arcsec)
RGS1 +53.6 \Gamma15
EPN +20 \Gamma80
Table 3: Inputs for calculation of SIAM v7. Numbers are additional apparent rotations of the
satellite w.r.t. the pointings generated from SIAM v5.
The shifts of R y appear to be systematically larger than was intended. With the absence of the
actual attitude histoR y
file, we cannot judge whether this is not due to a real offset in the pointing.
Similarly the shifts of R z for RGS prime appear slightly lower than requested. Again the attitude
histoR y
file would be required to track this down.
The most critical item is the small window of the MOS camers, which have a width of 100 \Theta
100 arcsec, so these 10 arcsec errors at max are not considered a problem.
3 New SIAM version 8
While this tests proved that all s/w is correct for the generation of the SIAM matrix, it has also
shown that the input of the requested offsets for the EPIC detectors was incorrect in sign. The both
angles for EPN prime and the angle of R z for RGS prime should have been inverted. We conclude
that a new SIAM is required with the following specifications:
Prime R y R z
Instrument (arcsec) (arcsec)
RGS1 +53:6 +15
EPN \Gamma20 +80
Table 4: Inputs for calculation of SIAM v8. Numbers are additional apparent rotations of the
satellite w.r.t. the pointings generated from SIAM v5.
Given this validation of the s/w, we feel confident that this SIAM can be generated, and no
further test of the pointing is required.
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4 Conclusion and Future Steps
Remaining byproducts of this test are the following observations:
ffl EMOS large window is ok
ffl EMOS small windows were not executed correctly and only one exposure of one camera was
successfully obtained. This needs to be verified for the other small windows.
ffl execution of FAST window mode of EMOS was unsucessful -- this probably needs an update
of the mode parameters
ffl Filing of data on­ground, as delivered to ESTEC seems inconsistent
We suggest the following steps to be taken from here on:
1. calculation of new SIAM with above requirements
2. update of rudi5 window parameters for OM; this invloves a change of the ops d/b
3. use of this test SIAM during any RGS wavelength calibration observation
Following this, these items need to be completed:
ffl A validation of the rudi5/fast small window settings is required, but no dedicated test obser­
vation is needed here. The validation can take place based on rudi5/image data acquired after
the SIAM was re­generated.
ffl similarly a validation of the EMOS small windows is required. This can be executed during
any upcoming RGS wavelength calibration observation.
There only the new SIAM should be used for RGS prime, only one pointing is required and
only execution of the windows should be performed.
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A Measurements with EPIC (DL)
A.1 with EMOS
OBSvn 0133120201 = PN prime
EXPECTED MEASURED
RawX RawY RawX RawY
MOS 1 241 307 385 270
delta from previous \Gamma74 +15 +70 \Gamma22
boresight
MOS 2 286 227 331 370
delta from previous \Gamma15 \Gamma74 +30 +69
boresight
This means that the position has changed in Spacecraft Y by +70 (expected \Gamma74)
and in Spacecraft Z by +25 (expected \Gamma15)
OBSvn 0133120101 = RGS prime
EXPECTED MEASURED
RawX RawY RawX RawY
MOS 1 296 243 321 239
delta from previous ­19 \Gamma49 +6 \Gamma53
boresight
MOS 2 350 282 360 306
delta from previous +49 \Gamma19 +59 +5
boresight
This means that the position has changed in Spacecraft Y by +5 (expected \Gamma19)
and in Spacecraft Z by +56 (expected +49)
A.2 with EPN
Roughly consistent but with ¸ 1 pixel error could be 4'' wrong (actually the R y
for the RGS prime
pointing is in better agreement with the measured values by the RGS and the OM than with the
MOS !)
PN Boresight has shifted Z +28 '', y +80''
RGS boresight has shifted Z +58'', y +12''
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B Measurements with RGS (CE)
I measured the position of the O VII transition on the detector for pointings with SIAM v5 (current
operational) and compared its shift with SIAM v7.
RGS1 RGS2
BETA XDSP BETA XSDP
(radians) (radians) (radians) (radians)
SIAM 5 5.663e­2 ­1.2113e­6 5.670e­2 ­6.076e­5
SIAM 7, RGS: 5.680e­2 6.010e­5 5.687e­2 9.509e­6
SIAM 7, EPN: 5.670e­2 4.054e­4 5.678e­2 3.473e­4
This implies the following rotations in the s/c coordinate system w.r.t. a pointing with SIAM v5:
for RGS prime
R y R z
from RGS1 64.5 \Gamma12:6
from RGS2 64.3 \Gamma14:5
for EPN prime
R y R z
from RGS1 26.5 \Gamma83:9
from RGS2 30.2 \Gamma84:2
C Measurements with OM (RM)
measured:
PN Boresight has shifted Z +18.9'', y +74.5''
RGS boresight has shifted Z +56.1'', y +9.9''
expected according to SIAM:
PN Boresight has shifted Z +15.1'', y +77.9''
RGS boresight has shifted Z +52.3'', y +14.1''
The difference between the measured and expected gives an estimate on the accuracy of s/c
pointing (and calculation).
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D Remarks and Conclusion of OM (RM)
The measured target position had an offset from the expected target position of 5.1 arcsec for the
RGS prime observation and 5.7 arcsec for the EPIC pn prime observation. Such an offset would
be critical for the operation of small windows, such as fast mode windows. However FAQ should
compensate for such offsets once fully operational and if executed. During the test observation no
FAQ took place, as the OM images were acquired in engineering mode 4 and no experience on the
FAQ under these circumstances was gained.
The procedure of the window position calculation was confirmed by the test observations and a
repetition of the test is not required after the re­generated SIAM including the required correction,
because the accuracy of 5 arcsec is sufficient for the rudi5/image configurations, especially that FAQ
is supposed to correct for this offset.
The new rudi5/image configurations will be re­calculated for the re­generated SIAM in an iden­
tical way as for the boresight test. No additional test is required.
A validation of the rudi5/fast small window settings is required, but no dedicated test observation
is needed here. The validation can take place based on rudi5/image data acquired after the SIAM
was re­generated.
E Comments about EMOS Data (DL)
While the main goal at the moment is to verify the pointing is correct, I briefly make some observa­
tions about the MOS readout modes as found in the odf files. There are a number of discrepancies.
the FULL frame modes not having changed have been used to verify pointing. Windowed modes
discussed as follows:
First of all as the exposures are mostly unscheduled it is difficult to match intended exposure #
with the unscheduled one:
OBSVN 0133120101 RGS Boresight test
ffl MOS1 exposure U003 --- probably supposed to be S007 --- small window. NO VALID DATA
IN THIS FILE
ffl MOS1 exposure U004 --- probably supposed to be S009 --- large window. Range of window
values ¸ 145--446 in X and 94--389 in Y. This is consistent with what was expected
ffl MOS1 exposure U005 --- there should not have been another windowed exposure --- should
have been timing. Reported data comes at windows 145­446, 93­390 so it is another large
window exposure!
ffl MOS2 exposure U003 --- probably supposed to be S010 --- large window Range of events in
window 200--500, 133--499, BUT NO EVENTS IN THE RANGE 197--319
ffl MOS 2 exposure 5 --- could also have been S010 --- large window --- range of events 199--500,
132--429 --- consistent with expected range
ffl MOS2 exposure U011 --- could have been S011 (timing) but then it has been mis­associated
to MOS 2 not MOS 1. range of window 303--393 is consistent with MOS2 --- but are there 10
pixels missing Tony ?
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ffl MOS2 exposure U012 could have been S012 (timing) --- again consistent with MOS2 timing
mode but 10 pixels short?
7 EXPOSURES 4 of which are failed or inconsistent data in pmsfits files!!!
OBSVN 0133120201 PN Boresight test
ffl MOS1 exposure U003 --- probably supposed to be S010 --- lareg window. Range of window
values 81--382,157--454 consistent with MOS1 large window
ffl MOS1 exposure U011 --- probably supposed to be S011 --- timing mode. Range of window
values 261--351 is NOT CONSISTENT WITH NEWLY EXPECTED LOCATION. Also ap­
pearance is rather ''blobby''
ffl Other MOS 1 exposures not found
ffl MOS2 exposure U003 --- probably supposed to be S010 --- large window Range of events in
window 135--436, 71--368 --- consistent with expected range
ffl MOS 2 exposure U012 --- could have been S012 (timing) --- NOT consistent with new MOS2
timing mode location
ffl Other MOS 1 exposures not found
6 window exposures expected --- only 2 seem consistent
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