ACIS Instrument Support - Monthly Progress Report for January 2017

1.  ACIS Characterization

1.3 Monitor scientific on-orbit performance of ACIS

  ...  Continued monitoring of ACIS CTI, gain, trailing pixel pulseheight, detector efficiency, corner pixel distribution, spectral line centroid and width, and focal plane temperature.  Updated monitoring web pages. (http://space.mit.edu/~cgrant/monitor.html).

  ...  Updated version of the ACIS monitoring software "catnrt" running on all SAO monitoring web servers.  This changes the flags used in starting pmon to match those used by MIT and Peter Ford.

  ...  Considering updates to pmon to add alerts for the newly discovered FEP thresholder anomaly (ObsID 18278 in December).
  

2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.  All engineering data remains nominal.
  
  ...  The EEPROM checksum was verified in the JAN1617 load.   Will continue to run monthly.  MIT telemetry processing will automatically check the results and send out an alert if the checksum is unexpected.

  ...  Ran a focal plane cooling test on January 17 in which the focal plane set point was changed to -126C.  At the end of the observation, the focal plane had reached -124.5C and was still dropping.  The rate of decrease was slightly slower than 2009, the last time this test was run, indicating there might be a very small degradation in the efficiency of the ACIS radiator.

2.2 Flight software maintenance

  ...  Flight software patch F-G-H (improved buscrash2) uploaded in June 2014.

2.3 Instrument science performance

  ...  Participated in monthly ACIS operations meetings.  Discussed potential DPA-B shutdown anomaly scenarios, the ObsID 18278/FEP thresholder anomaly, and the focal plane cooling test.

  ...  Prepared slides for the bakeout telecon in February summarizing the MIT team work on understanding and quantifying the flight experience with cold irradiation and bakeout.

  ...  Continuing to review new ACIS quick-look anomaly reference web pages.  Worked through DPA-B shutdown scenarios and potential responses.

  ...  Continued investigation into new FEP thresholder anomaly during ObsID 18278 in which one CCD/FEP started telemetering only every other frame.  Memo describing anomaly and the possible cause released in January. (ftp://acis.mit.edu/pub/acis-18278-anom-v1.2.pdf)

  ...  Attended FOT training sessions on PCAD and ACA systems.

  ...  Continued daily quick-look processing of ACIS telemetry and maintained Web interface to ACIS real-time data.  

  ...  Continued to publish the "annotated DOT" timeline reports.

2.5 Participate in Chandra activities


3.  CXC Support

3.1 Provide user support

  ...  ACIS memo listing calibration ObsIDs and observation characteristics (ACIS Memo #165) will no longer be updated.  Functionality is replaced by new web page (http://acis.mit.edu/asc/evt-page.html), which provides the same information but is more automated.

  ...  Worked with USINT to reconfigure AO-18 observations that were not assigned SI modes due to errors or warnings produced by the ACIS command generation software.

  ...  Reviewed article from ACIS operations team for Chandra newsletter.

3.2 Provide data analysis support

  ...  Participated in CXC Cal/Ops ACIS response discussion group.  Discussed updates to tgain and to the temperature-dependent CTI correction and bakeout simulations.

  ...  Answered question from Cal scientist on why tgain not applied to some ECS observations in the archive.  They were outside of the "valid" temperature range that was being applied at the time they went through the processing pipeline.

  ...  Continued to maintain ACIS calibration database of ground and flight data products.

  ...  Examined bias frames from previous big dither calibration observations in which the dither is disabled during the bias.  No source was detectable in the bias frames.


4.  OCC Support

4.1 Use of MIT/ACIS EGSE at OCC

  ...  Continued support and maintenance of ACIS EGSE software and hardware at the OCC.  Performed monthly check of all ACIS hardware and software in the TST room at the OCC.

  ...  Working on better documentation of the ACIS EGSE machines, particularly for anomaly recovery response in the absence of an expert user.  Updated web page.

4.2 Generation of commands for ACIS observations

  ...  Continued review and updating of SACGS documentation (SACGS = SOT ACIS Command Generation System).  Updated OR list review documentation to add warnings for solar system objects or other non-standard pointing.

  ...  Continuing familiarization with SACGS operation and under-the-hood functioning.

  ...  Built three new SI modes and updated one SI mode for potential future chip drops.  This covers all 1-, 2-, and 3-chip drop contingencies down to two CCDs for all unobserved ObsIDs as currently configured.  Installed new ACIS tables at the OCC in February.

  ...  Discussed modernization of SI modes and how the video offset update was done in 2011.  Checked historical observations of solar system objects, many modes are now outdated, but are seldom reused.  Updated software that feeds SI mode finder web page to remove outdated modes from the display.

  ...  Fixed a bug in the ACIS ruleset which generated duplicate parameter blocks when the lower energy filter was set to 0.36 keV for ACIS-I observations.  There was a mismatch between the KeV to ADU conversion used for the filter and a lower limit applied later on.

  ...  Reviewed JAN3017 preliminary schedule, post-final OR and post-post-final OR.  Reviewed JAN3017A command loads.  Reviewed FEB0617 preliminary schedule and final OR lists.  Reviewed FEB1317 Long Term Schedule OR list.

  ...  Reviewed JUL0116S test command load.

  ...  Dropped chips from ten obsids.  Assigned eight SI modes.

  ...  Assisted with SI mode build and installation of ACIS tables at the OCC.

  ...  Updated software that checks for observations with blank SI modes to search older AOs, since each AO is getting more spread out in time.

  ...  Checking on automated processes associated with SACGS.