1 / 24

Presented by P. Mosner/R. Geßner Astrium GmbH

MIPAS In-Orbit Operation. Presented by P. Mosner/R. Geßner Astrium GmbH. Contents. Part1 (P. Mosner) : Switch-On and Data Acquisition Phase (SODAP): History MIPAS Anomalies (1) - Mechanisms Modifications to Operational Procedures. Part2 (R. Geßner) :

loe
Download Presentation

Presented by P. Mosner/R. Geßner Astrium GmbH

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MIPAS In-Orbit Operation Presented by P. Mosner/R. Geßner Astrium GmbH

  2. Contents • Part1 (P. Mosner) : • Switch-On and Data Acquisition Phase (SODAP): History • MIPAS Anomalies (1) - Mechanisms • Modifications to Operational Procedures • Part2 (R. Geßner) : • MIPAS SODAP and CAL/VAL Characterisations • Operational Aspects of Instrument Performance • MIPAS Anomalies (2) - Miscellaneous • Long-Term Observations • Summary

  3. Part 1

  4. MIPAS Switch-On and Data Acqusition Phase (SODAP) - History • Locking of MIPAS coolers at L – 6 hours 28 February 2002 • Launch01 March 2002 01:07 UTC • Principal MIPAS switch-on Sequence during SODAP • ICU switch-on 11-13 March 2002 • -> OLB-B thermostat anomaly, was resolved later • Unlocking of ASU, ESU, INT 17 March 2002 • Transition Standby -> Heater 18-19 March 2002 • Cooler and CBB characterisation 20-23 March 2002 • First MIPAS measurements 24 March 2002 • Timing characterisations 24-26 March 2002 • Handover to MPS 26 March 2002 • SODAP -> CAL/VAL Phase handover begin April 2002

  5. MIPAS Anomalies (1) - ESU stepsize limitation • A HEATER MCMD resulted in a transition to HTR/REF Mode • Explanation : • the Heater MCMD occurs at a time where the requested Heater Mode transition can cause a conflict with activities finalising the ongoing sweep • this occurs only if ESU step sizes larger than the instrument specification value are commanded, which was demonstrated by tests on EQM at Ottobrunn • Operational solution: • every Heater MCMD is preceded by an Elevation Wear Cycle (in this case the surveillance related to the failure is inhibited for a short period of time) • BUT: the conflict may occur for other type of commanding where such a solution is not possible

  6. M1,M2 M5,M6 M3,M4 Slide 1 stop after init Slide 1 End Stop Slide 2 stop at neg. end Neg. End Slide 2 Positive Direction Pos. End LockPosition Initialisation Marks MIPAS Anomalies (1) - Interferometer initialisation • An IDU re-initialisation failed (after non-nominal switch-off) • Explanation : • After a non-nominal IDU switch-off it can occur that both IDU slides are outside the init marks (Slide 1 being at positive APS side, Slide 2 at negative APS side. If this is the case the failure occurs due to • The slide 2 stops than at the neg. end stop behind the lock position • The lock position rail insert presents a small step on the rail where a velocity error can occur

  7. MIPAS Anomalies (1) - Interferometer initialisation • Operational solution: If the IDU isn’t initialised after the transition from Standby to Heater, it is required to perform 3 times the following initialisation steps after reaching Heater Mode: - initialise the IDU slides - move slide 1 to the negative rail end and slide 2 to the positive rail end

  8. MIPAS Anomalies (1) - Cooler performance • MIPAS instrument was switched off due to cooler vibration failure • Failure Observations and Explanation : - The cooler accelerations increased extremely (acceleration increase from <3mg to 12 mg; 1st harmonic acceleration increased by 50 times)This was caused due to loss of proportionality between compressor/displacer B drive level and amplitudes/PPO outputs • The proportionality for compressor B failed due to a mis-adjustment of the phases and amplitudes for the 1., 2. and 3. harmonics by the VCS. All of these harmonics correction products are processed and corrected individually. • The probable reason was the ageing of the VCS setting due to the long “on-line” operation without a repeated learning cycle • Operational solution(still under discussion): • Every 2-4 weeks (TBC) perform 5 VCS re-learn cycles (in Heater Mode) • If the failure re-occurs stop and re-start cooling once per month

  9. Modifications to Operational Procedures • Mode Transition Standby to Heater: • Special IDU initialisation to correct IDU init problems • Start Measurement: • Update PAW gain setting for Measurement (switch PAW table 1) • Stop Measurement (Trans. Measurement to Heater): • the Heater MCMD is preceded by an Elevation Wear Cycle to allow the higher elevation stepsize (as discussed before) • Update the PAW gain setting, if a LOS/CAL sequence follows (PAW table 2) • Non-Linearity Characterisation: • New procedure added • Change due to limitation from the non-availability of ARTEMIS • Update SPE filter set: • Procedure added

  10. Part 2

  11. MIPAS Characterisation in SODAP and CALVAL • Timing Characterisation • Mode Transition Times • Duration of Operational Sequences • Temperature Characterisation • MIPAS Optics Module / Interferometer • Calibration Blackbody • MIPAS Anomalies: Complementary Failures

  12. OFF Functions 11.050 sec 11.052 sec BB CAL Nom. MEAS 20.000 sec 20.035 sec DS CAL SEM < 55 hrs 35.5 hrs 10.200 sec 10.203 sec HEATER STANDBY LAUNCH LOS CAL 11.050 sec 11.063 sec 20.000 sec 20.014 sec MIPAS Timing Characterisation: Mode Transition Times • Correlation between MCMD TT and time stamp of Source Packet

  13. MIPAS Timing Characterisation: Summary (1) • Mode Transitions : • Heater to Measurement:20.035 sec  5.9 ms - > higher than values on-ground due to shift of ZPD position to align forward and reverse sweeps; effect understood • Heater to LOS CAL:11.063 sec  0 ms(IOM: 10.066 sec) 20.014 sec  8.2 ms • Meas. to SEM,DS,BB:11.052 sec  5.9 ms 10.203 sec  3.9 ms

  14. MIPAS Timing Characterisation: Summary (2) • Duration of activities: • Elevation Scan Sequence (ESS - 16 high resolution sweeps): 71.202 sec  5.8 ms(design value: 71.200 sec) • ESS Sequence (5 ESS + Offset Calibration): 387.610 sec  8.4 ms(design value: 387.600 sec) • INT turnaround time: 0.450 sec  4.5 ms(design value: 0.450 sec) • Low Resolution Sweeps: 0.400 sec (0.4 sec) • Medium Resolution Sweeps: 2.002 sec (2.0 sec) • High Resolution Sweeps: 4.003 sec (4.0 sec)

  15. Interferometer temp MIO Baseplate temp MIPAS Temperature Characterisation: Optics Module • MIO temperature increase in the mission: 216 K (L+10 days) -> 221 K (L+25 days) -> 224 K (L+ 68 days) • MIO baseplate orbital temperature variation: 0.2 K p-p, but Interferometer remains very stable (hence also the Beamsplitter)

  16. MIPAS Temp Characterisation: CBB Temperatures (1) • CBB temperature profile shows 3 effects: • Temperature increase by about 1.7 Kwhen MIPAS is switched into Measurement Mode - > ASU shutter opens and the CBB sees parts of the atmosphere via the side baffle • Temperature change by about 3 Kwhen CBB heater level is changed by one step (0.27 W) • Orbital oscillation by about 0.2 K

  17. Orbital variation MIPAS to Measurement CBB HL= 6 CBB HL= 4 CBB HL= 5 MIPAS to Measurement MIPAS to Heater Mode MIPAS Temp Characterisation: CBB Temperatures (2)

  18. MIPAS Temp Characterisation: CBB Temperatures (3)

  19. Operational Aspects of Instrument Performance • Radiometric, spectral or ILS performance : no operational impacts so far • LOS pointing performance: • analogue gain setting needs to be increased for LOS Calibration (poor signals especially in Channel D2) • first LOS signal (crosscorrelation peak) in a series of star measurements still earlier than expected; no major impact since other measurements “rectify” the CC peak; nevertheless explanation required • Gain measurements reveal some deterioration of optical throughput in the range of a few percent;could be contaminants (ice) on the detectors -> similar effects observed on other ENVISAT instruments -> operational impact for MIPAS: may require Decontamination Heating -> however: risk of this kind of cooler operation needs to be traded against the performance degradation -> going back to STANDBY (Coolers OFF) may be sufficient

  20. MIPAS Gain Drift of about 6% within 224 orbits (about 15 days)

  21. MIPAS Anomalies (2) - Complementary Failures • SPE related error messages • Occasional “SPE correctable memory fault” reporting (EDAC) • Occurrences of an “unexpected sample count” - no impact on GS detected so far (not all L0 data available) • Occurrences of “ICE AUX Data not included” (5-6 events per day - but relatively poor statistics) - results in a loss of the SP’s from the respective sweep -> seems to be SPE-ICE communication problem - not correlated to Orbit position nor Instrument activity - not observed during EQM testing initiated immediately in OTN -> not really understood -> to be observed

  22. Required Long-term Observations (1) - MIPAS Mechanisms • ASU/ESU : • Lifetime limited aspects (ESU leadscrew rotations) - some margin • Interferometer: • Monitor the warning anomaly flags (history reporting at ESOC)- Slide Movement Force Warning (1N Force)- Differential Speed Warning (1.5%) • Monitor fringe count errors (via Measurement data analysis) • Lifetime limited items: Number of INT sweeps - depends very much on operational scenario - see updated MIPAS IOM; little margin • Cooler: • Monitor Cooler Vibrations (Compressor/Displacer acceleration and harmonics) • Monitor Temperature stability (stability flags) • Monitor warning anomaly flags (ICU anomaly counts) • Important: take cyclically RTT formats (twice per orbit)

  23. Required Long-term Observations (2) - Others • Statistics on source packet losses : • evaluation of history entries required • Evaluation of life limited items : • depending on operational scenario - see previous page • Optical throughput : • needs to be observed together with NESR evaluations to decide whether detector warm-up is required

  24. CONCLUSIONS • MIPAS functional and operational behaviour excellent • Characterisation data is as expected and very accurate • Operational measures for detected anomalies in place • Long-term observations required on mechanisms and on source packet losses • Documentation: MIPAS SODAP Report + CAL/VAL extension

More Related