IOCG Closed Issues

 
Issue Raised Notes
Most of sky 'invisible' in Rev 1291 Mail by E. Kuulkers
(26 April 2013)
  • Discrepancy between bubble plots and ISOC visibility.
  • Analysis found problem in oveerlapping Earth and Moon eclipses during Rev 1291. Solved by new eclipse file.
Position angle variations in POSes Mails between C. Sanchez & A. McDonald
(12 April 2013)
  • Position angle not maintained during perigee passages. Noted for Rev 1281 forward, but possibly much older issue, which has usually remained 'below the radar'.
  • Caused by different schemes for perigee passage between first plan and subsequent ones. Warning to be added to ISOC planning software.
Only use Open Loop Slews Mail by P. Kretschmar
(30 Mar 2012)
  • Due to startracker detoriation, closed-loop slews more frequently can not be done correctly and a corrective manoeuver is done.
  • This could be avoided by having only open-loop slews
    => slew accuracy drops to few 10 arcsec.
  • Test done in Rev 1222, but affected by bug in ISOC software.
  • Software updated (v33.2), successful test in Rev 1250.
  • Implemented from Rev 1266, 24 Feb 2013 (OCR 332).
Shadowing of -Z antenna by SPI Mail R. Southworth
(12 Jan 2012)
  • Evidence seen in recent weeks, might be caused by combination of orientation, very high apogee, possibly aging of transmitter,
  • Might imply change in RF switching strategy.
  • Flight Dynamics implemented new S/W to avoid this in August 2012 (week 32).
ISGRI energy response out of date IOCG Meeting #02 by
R. Walter
  •  OSA-10 released on 24 Sep 2012
Data right flags for proposal 0930024 (GX 304-1) Mail by C. Sanchez
(14 Mar 2012)
  • Database & IOP updated, but POD files are not guaranteed to hold current information, as they are sent when revolutions are planned.
  • Only IOP to be used. ISOC/ISDC ICD has been updated (v2.9).
Introduction of randomized dither patterns? Proposed at ISWT splinter meeting,
29 Feb 2007 
  • Ideas prepared by ISOC and presented at GS Co. Mtg. 12
  • Any new pattern would need deep study first.
IBIS (also) saturates telemetry Mail by AB to ISDC
(05 Mar 2008)
  • Visible problems especially in Rev 656.
  • Partially caused by configuration of Noisy Pixel Handling System, which was not adapted for higher background.
  • Changed parameter MCM from 10000 to 20000, improving NPHS reaction
  • Later, e.g., in Revs 682-685 observing Cyg X-1 or in Revs 739 & 741, telemetry is again saturated.
  • Meeting at 8th Integral Workshop to discuss TM distribution.
  • No longer an issue due to higher solar activity (2011).
IMU for 16000 s INTEGRAL AR 3185
(10 Aug 2011)
  • If IMU is switched on during eclipse season it has a minimal on time of 16000 s, leading to lost slews. This happened in Rev 1077.
  • Old constraint (from industry?), also for XMM. Recovery procedure changed to sensible approach. (Mail by R. Southworth, 21 Nov 2011)
Incorrect sequence of EDs to OMC Mail by R. Southworth
(18 Apr 2011)
  • Wrong ED sequence in commanding OMC FF Calibration (see also Action in ARTS).
  • Resolved by allowing for sufficient time of second observation (2 ks). See ISOC SPR 1302.
Problems with Rev 1003 Mail R. Kresken
(20 Jan 2011)
  • No valid reaction wheel profile found.
  • Various attempts to modify planning or add RWB possibility.
  • ISOC s/w allows placement of extra slews in slew window (Mail by E. Kuulkers 17 Feb 2011)
Late ISGRI activation Mail F. Lebrun
(22 Jan 2011)
  • Sudden raise in height of belts from Rev 1006, affecting ISGRI.
  • OCR 299 raised routinely to shift perigee exit height by 3000 km from Rev 1010 on 24 Dec.
  • G. Bélanger has developed a model based on harmonic analysis and circulated. To be compared with real evolution.
  • Agreed in video-con to follow a cautious approach until more data is available.
Bad time data in JEM-X packets Mail by C. Ferrigno
(28 July 2011)
  • Several science windows for JEM-X had a clock anomaly (OBT=0), leading to rejection in the processing.
  • Known issue of DPE SW on-board, not fixed since it rarely becomes apparent (mail S. Brandt, 23 Aug).
  • ISDC S/W updated to handle this correctly.
Problems with PSFs for Revs 896ff Mail by G. Bélanger
(01 Feb 2010)
  • Problem caused by order of tags for events that have no difference in time. Either ISOC or MOC software needs updating.
  • SCREW 1246 raised on ISOC software. Closed in ISOC S/W V29.1.
JEM-X DFEE CRC anomaly Repeating issue, anomaly INT_SC-238
  • OCRs 240 and 241 raised to test DFEE behaviour.
  • Anomaly appeared for JEM-X 1 following eclipse on 13 Feb 2011. New procedure has been defined.
Complications in planning Rev 978 Mail R. Kresken
(14 Oct 2010)
  • Almost impossible to get slews right, even after moving S/C calibration to later revolution. In total 11 attempts with multiple interactions between MOC and ISOC.
  • Videoconference MOC/ISOC on 26 Oct 2010: various issues identified, next attempt at AOCS calibrations in early 2011.
  • Traced back to different magnitude limits for access of star catalogue. AOCS calibration with fix done in Rev 1030 (21 March).
Timing offset (30 μs) from Goldstone Mail R. Southworth
(22 Nov 2010)
  • Reason unclear, but constant. Easily corrected for regenerated TCO data.
  • Goldstone DSN no longer in regular use.
NRT data flow from MOC to ISDC interrupted XMM-INT-WOPS-10_32
(18 Aug 2010)
  • Situation happened twice on 11/12 Aug and on 15 Aug 2010.
  • Possibly caused by 'back pressure' on servers if PI workstations cannot receive data.
  • Steps have been taken to avoid this situation.
Problems processing consolidated telemetry at ISDC Mail by R. Walter
(11 June 2009)
  • Serious problems in Rev 795 and 800 at least.
  • Major manual work at ISDC to fix this in manual work and using NRT data.
  • Problem identified for Rev 800 and fixed at MOC.
Low perigee passage could lead to violation of ITU regulations Mail R. Southworth
(19 Feb 2010)
  • Probably easy to solve by switching transponders off for closest part of orbit (outside groundstation contact anyway) with timeline commands.
  • Transmitter switching successfully tested during Rev 908 (23 March 2010).
  • First implementation at end of Rev 960 (26 Aug 2010). Success confirmed by R. Southworth (27 Aug 2010).
Question of exact startracker alignment Mail by R. Walter
31 Aug 2006
  • Possibly thermal effect between startracker and IBIS. Could be startracker rotating around Z axis by ~20 arcsec.
  • Alenia considers this impossible (max. ~7 arcsec in their modeling).
  • Blurs the resulting image for large mosaics and limits source cleaning and thus sensitivity for weak sources.
  • Clear trend also seen in JEM-X and OMC data but no straightforward connection, as each instrument has its own deformations as well.
  • Fixed in OSA 8.0 (31 Aug 2009).
Renewed time correlation problems Mail by R. Walter
(01 Oct 2009)
  • Divergence between two ground stations of >100μs from Rev 796 on.
  • Occasional problem in generating TCO data identified. Software is being upgraded.
  • Updated TCO data created by MOC on 9 Feb 2010 and subsequently verified. ISDC keeps checking time correlation.
Time correlation apparently much less stable than specified Mail by R. Walter
13 Apr 2007 
  • Issue discussed at GS Coordination Meeting 12 (Toulouse)
  • Further discussed at IOCG Meeting 01.
  • New checks done at Toulouse (mail of JPR 26 Aug 2008). Still some deviations.
  • Updated TCOR information has been provided by MOC (18 Sep 2008) and processed at ISDC. Will be checked by Toulouse (mails on 01 Oct 2008).
  • Will be fixed in rev_3 of the ISDC archive (early 2010)
Wrong TM settings in Rev 716 Mail by A. Domingo
(26 Aug 2008)
  • Problem caused by error in uplink of PST, thus that instruments remained at: SPI 100, IBIS 56, JX1/2 9, OMC 5, instead of the planned [SPI annealing]: SPI 30, IBIS 180, JX1/2 15, OMC 9.
  • Not caught for various reasons, see ARTS INT-3020.
  • ISDC developed script for checking (29 Aug 2008).
  • PST during startup will be changed to one closer to actual usage, this is ongoing.
  • New ED was implemented and tested succesfully.
Problems with handover windows in revolutions 845 + 846 Mail by C. Sanchez
(25 Aug 2009)
  • Under investigation at ISOC
  • SPR 1094 was raised at ISOC and closed.
Next SPI annealing date Mail by A. Parmar
(20 May 2009)
  • Cryocooler power supply becoming marginal with just one unit towards end of inter-annealing cycle, but switch to two failed (29 April, under investigation).
  • Annealing #13 did not recover resolution fully.
  • Agreed on 15 Sep 2009 to have annealing #14 begin in Rev 857 (19 Oct).
Mail address #integralogs @ MOC not working properly Mail by R. Southworth
(10 June 2009)
  •  Replaced by list maintained at ISOC integralogs@sciops.esa.int.
FTP problems downloading KP data from ISDC Mails by various users
(from early Dec 2008)
  • A network switch had to be fixed at ISDC and the Univ. Geneva had problems, but the exact cause is still unknown. 
  • Disabling of a firewall at ISDC resolved the problem (Jan 2009).
Gap in consolidated data sent to ISDC Telecon ISOC/ISDC
(18 Nov 2008)
  • Gap causes long delay in delivery of data to users.
  • Was fixed by CDs sent on 4 Nov by MOC.
Problems planning AOCS pointings in Rev 562 Mail by E. Kuulkers
11 May 2007
  • ISOC cannot schedule pointings across a handover period -> may need update of ICD with MOC.
  • Constraint checking not identical between MOC & ISOC.
  • Updated FD software made available 30 Jan  and again 19 Mar 2008, but numerical problems still found at ISOC (mail PJB 18 Feb & 19 Mar 2008).
  • Another update made available on 07 Aug 2008. Successfully tested and included in ISOC V19.4
Constraint violation in Rev 461 Mail by A. McDonald
12 July 2006
  • Revolution includes 'micro-eclipse' of Sun by Moon and could only be planned by changing constraint checking.
  • Apparently caused by FD software 'masking' constraint violation because of eclipse.
  • Work-around by manual intervention at MOC.
  • TSF first caused problems at ISDC, solved by manual intervention of MOC and new TSF.
  • Bug found in FD software, mail by C. Lozano (20 Dec 2006), action opened to have problem fixed.
  • Fixed in updated FD software (see above).
IFTS problems end April 2008
  • Caused by wrongly changed firewall settings done by Corporate Services without consultation.
  • Firewall configuration updated. Additional safety mechanisms (ISOC SCREWS 694, 695) implemented in ISOC system V19.3 (15 Jul 2008).
PST over-allocation to make use of 3 more packets Idea raised at GS Coord. Meeting 13
(06 Nov 2007)
  • TN circulated by R. Southworth (10 Dec 2007)
  • OCR 229 for test raised by R. Southworth (10 Dec 2007), agreed by PS & ISDC (10+11 Dec 2007).
  • Used as baseline for revolutions with standard TM allocation from 11 Feb 2008 onward through manual intervention of SPACON.
  • Technical Note issued on 25 Feb 2008.
  • New scheme of increased fixed allocation to SPI (+3 packets) implemented as baseline at MOC from Rev 659 (Mail by F. Cordero, 4 Mar 2008).
  • Implemented at ISOC from Rev 691 onward.
SPI photon telemetry compression Idea raised at GS Coord. Meeting 13
(06 Nov 2007)
  • Following study by F. Cordero, implemented in IASW 434.
  • SPI IASW patch 4.3.4 uploaded 28 Jan 2008 and modes successfully tested.
  • INTGSCCR-88 raised by F. Cordero 11 Feb 2008, approved by SOM 13 Feb 2008.
  • Database update received and new decoding algorithm implemented at ISDC.
  • Function activated 06 Mar 2008, before radiation belt exit of revolution 659.
New thresholds for PICSIT in PPM during SLEW Reaction to action Co/13-02
  • INTGSCCR-87 raised (06 Dec 2007).
  • Implemented from Rev 657 onward.
Increased out-of-limits and radiation effects on the approach to 'belt entry' for JEM-X Mail by M. Walker
27 Nov 2007
  • JEM-X team agrees to raise belt entry attitude to 60000 km from 56000 km.
  • Implemented from Rev 648 onward by MOC.
  • Set back to 56000 km from Rev 659 onward.
Optimum raster strategy for IBIS Discussion at IUG & ISWT Meetings
09-11 Oct 2006
  • Some specialists would prefer a (randomized?) rotation around the pointing axis after each cycle.
  • F. Lebrun points out that rotation does not remove all issues.
  • Agreement at GS Coordination Mtg 11 to implement rotation of instrument & pattern after each cycle by 6/(N_grid-1) degrees.
  • Implemented in ISOC V16.0.1 (Nov 2007)
Instrument activation in rad. belts Mails by S. Fahmy
and O. Bergogne
03 Apr 2007
  • Problems reported for IBIS & JEM-X, but also SPI reported rad. belt effects for Rev 541.
  • Proposal to delay instrument activation for ~1h, by setting CRIT_INST_ALT_ASC to 53000 km instead of 45000 km.
  • Used since Rev 555 (30 April).
Constraint violation in POS 558_08 Mail by Integral ADC team
03 May 2007
  • Roll angle constraint was violated by 0.05 deg
  • Should have been caught by planning software at ISOC.
  • Orbit files appear to be the same.
  • Several iterations between ISOC & MOC.
  • Decision by Flight Dynamics to not pursue the issue further (call by F. Dreger, 19 June 2007).
Installation of IASW v433 for SPI OCR-223, F. Cordero
27 Jan 2007
  • Marked as GS CR as it effects on ISDC and mission planning.
  • IASW patch implemented between Rev 531 and 532 (mail by SF 23 Feb 2007). Spectral scaling tested in Rev 536.
  • One anomaly found. OCR 225 for patch submitted 04 Apr 2007.
  • OCR 225 implemented, 12 April (perigee passage 548/549).
Wheel bias too close to Handover Mail by A. McDonald
26 Oct 2006
  • Preferably ISOC would ensure a 3 minute time interval between handovers and SOPS(WHEEL_BIAS) windows.
  • P. Balm proposed to use new HO_PERIOD START/STOP keywords to ensure this.
  • After discussion at MOC, different approach taken:
    MOC will move the change guide star ED from the end of the handover interval to two minutes before the start of the handover, at the end of the previous exposure.
  • Procedures at MOC have been updated
    (Mail A. McDonald, 18 Apr 2007)
IBIS VETO toggling of the PMT 28 V Mail by O. Bergogne
12 Oct 2006
  • Anomaly first reported on 18 Nov 2004.
  • Reported value seems to diverge more lately.
  • Mail from Piotr Orleanski on 13 Oct 2006 confirms trend (~1%/year) in PMT voltage. Probably OK for several more years but needs confirmation by specialists.
  • High soft limit for TM parameter G8015 will be raised from 29.4V to 30.8V, as agreed by VETO team.
Infavourable orbit evolution Mail by M. Schmidt
18 Sep 2006
  • Orbit evolving unfavourably since May and may run into problems within 1-2 months.
  • ISOC to use suggested Perigee Passage attitude from Rev 482 onward if not negative for use of science time.
  • FD has optimized procedure to make best use of available RWBs also those not at perigee passage.
Command history files incorrect Mail exchange
M. Schmidt & R. Walter
07 Sep 2006
  • S/W at MOC currently produces files with errors. This will be fixed in time but for past data the files will not be reproduced.
  • An alternative strategy exists and files are created manually for IBIS team and ISDC as intermediate solution. This is acceptable to ISDC.
Problems with PSFs for Rev 473ff Various mails 16 Aug 2006 ff
  • For Rev 475 the problem is that a GSHO straddles the Perigee Entry which ISOC treats as pointing.
  • At a telecon with FD on 20 Sep 2006 it was agreed to change the PSF format such that a new window HO_PERIOD would be included which is the actually allowed interval to place a handover.
  • ISOC SCREW 581 raised as GS CR on 25 Sep 2006.
  • HO_PERIOD START/STOP keywords included in PSF ICD 2.6, to be signed in February
  • ISOC system V14.4 supports new format.
  • First used in PSF for Rev 546.
Planning & handling JEM-X Test Mode GS Coord. Meeting #10
  • No change required at MOC (parameter of Data Taking ED)
  • ISOC needs to update planning software
  • ISDC & JEM-X agreed on handling, very similar to memory dump data (ISDC SCREW 1820).
  • Software running at ISDC.
Radiation Belts configuration changed and no longer well matched by planned time sequence. Mail by S. Brandt
10 July 2006
  • JEM-X HV switch-off triggered by HW triggers beyond limit.
  • Confirmed in TN circulated by MOC based on IREM data and by Radiation Belt monitoring at ISDC (17 July).
  • Mail sent to ISWT and others, by PK 19 July.
  • Email disscusion converging on general shift to 30 minutes later planned belt entry and exit, with slightly different handling for JEM-X.
  • General shift to 30 minutes later planned belt entry and exit, with slightly different handling for JEM-X implemented from Rev 464 onward (INTGSCCR-85).
  • JEM-X reports improvement (mail by SB 17 August).
  • Results confirmed by SPI (mail by RD 25 August).
SPI annealing periods not flagged in POD Mail by N. Mowlavi
16 May 2006
  • No definition in ISOC IFOM which Mode to select. ISDC SPI specialists would prefer "Configuration".
  • Finally ISDC decided not to request any change
Changed PAD/IOP format (ISOC/ISDC ICD) Mail by P. Balm
to M.Beck
17 July 2006
  • Schedule agreed between ISDC and ISOC for implementation
  • Test file sent to ISDC and judged OK 21 July 2006. AO-4 PAD to be sent after installation of system 12.6 at ISOC.
  • AO-4 PAD sent formally on Tuesday 08 Aug 2006
Increased pointing error Mail by M. Mas
02 Jun 2006
  • Noted by large recentring offsets for OMC in GPS of Rev 443.
  • Resolved after AOCS calibrations in Rev 446 (mail by A. Domingo 23 Jun 2006)
SPI TM bandwidth saturation Mail by F. Cordero
08 Feb 2006
  • ISWT#39: Transfer one packet from IBIS to SPI
    (see GS CR and OCR-210)
  • Meeting of Telemetry Working Group at Frascati, 12-Mar decided to give JEM-X 2 HK packet to SPI (GS CR,, ISOC SCREW 543) and to make changes to SPI telemetry.
  • Packet given from JEM-X from Rev 441 onward.
  • Succesful tests at MOC & ISDC
  • Successfully implemented after SPI annealing from Rev 454 onward.
Planning of AOCS calibrations Long-standing issue between ISOC & MOC
  • Undestanding reached on file formats to be used. Tested for revolution 446.
IBIS occasional TM bandwidth saturation TWG Meeting, Frascati, 12 Mar 2006
  • Changes to PICsIT SPTI configuration
  • GS CR issued by G. La Rosa 21 Apr 2006
  • Changes at ISOC & MOC implemented from Rev 441 onward (24 May 2006)
JEM-X GTI largely "bad" for observations of Sco X-1 due to extremely high countrates. Mail by S. Paltani
11 Apr 2006
  • ISDC offered (18 May 2006) to supply new tool in GTI step, if JEM-X team provides exact description of algorithm and values.
  • JEM-X delivered new Good-Time limits table with very large countrates still considered 'good' (23 May 2006). Further selection to be done by user.
Unclear responsibility for informing PI's in case of TOO sources detected at ISDC to meet their trigger criteria. Mail by N. Mowlavi
18 Apr 2006
  • Expected behaviour (ISDC informs) clarified with Project Scientist (19 Apr 2006)
  • ISDC has changed procedure accordingly.
Systematic error in time correlation Mail by M. Schmidt
07 Feb 2006
  • Problem identified at Redu: missing 47.03 µs correction.
  • Not confirmed by pulsar studies
  • Decision: no change currently, if necessary could be corrected in future revision of INTEGRAL archive.