1. 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE UVIS TEAM MEETING OPERATIONS UPDATE 1

2. 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE Instrument Status On/Off Cycle: 27. –No change since last meeting. Hours On: ~86,100 hours. –Continuous operations since 9/11/2007. –Longest continuous operations. HDAC Filament Modulation: –Filament 1: 115.28 hours (H cell), 100.28 (D cell). –Filament 2: 12.22 hours. –Last: In S59 during T67 (H cell only). No modulation between 2006/255 & 2010/28 2

3. 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE Significant Issues S58UVIS_127TI_M60RT3CLD065_ISSSignificant data lost due to DSN problem. S59UVIS_130OT_OUTERSATS001_ISSLost due to DSN problem. 3

4. 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE First Time Event First off-axis star occultation using the FUV occultation slit: –T70 (2010-172) UVIS_133ST_ALPVIRTI001. –Set up tested in S54 (off by 1 pixel). –Set up tested in S59 (looks Ok). 4

5. Off-axis Occultation Setup Pointing: FUV to star with (-23.968,0.0,0.0 mrd) offset Window setup 55,59,1,1,1024,1 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE5 S59 test

6. Off-axis Occultation Setup 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE6

7. UVIS_133ST_ALPVIRTI001 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE7 Counts vs time

8. UVIS_133ST_ALPVIRTI001 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE8 Record 100-200 Record 400-500

9. New Instrument Setup HSP with no compression during calibration (first in S61 2010/178). HSP with no compression during F-ring crossing when this makes sense (first in S61 2010/186). 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE9

10. New Instrument Setup IPHSURVEY in LORES (vs OCC) during rolling downlink. Slits are moved to HIRES if UVIS is inactive for more than 5 hours. –Favors LORES 1 (the nearest from HIRES clockwise) instead of LORES 2. 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE10

11. FUV/EUV Slit Usage 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE11 LO_RES_1 OCC LO_RES_2 HI_RES OCC HI_RES LO_RES_2

12. Bob’s EUVFUV “Template” No a real plug & play template possible: –Not the same duration. –Not the same viewing geometry. Documented a set of rules to design the EUVFUV scans based on the maximum angular size of Saturn (or Titan) during the scan. 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE12

13. Bob’s EUVFUV “Template” Design constraints: –20 minutes turn time to and from the WP. –Start/Stop mosaic: 240 seconds dwell time. 0.006 mrd/s scan rate. –When possible scan from limb to limb (or from top of exobase to top of exobase). 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE13

14. Bob’s EUVFUV “Template” Works reasonably well for Saturn: –Breaks down when FRs are violated. –Breaks down when target angular size is much greater than the slit size. Helpful for Titan FB. –But viewing geometry is changing rapidly. 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE14

15. Ring/Dust Xing Provided Candy and Amanda with some details on two dust crossings. UVIS had one dust crossing during a rolling IPHSURVEY (time resolution 12.5 sec) –Provides a way to calibrate background noise knowing the TM rate. –UVIS_127SW_IPHSURVEY020_RIDER ( 2010- 062T02:55:00 to 2010-062T12:19:00) 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE15

16. UVIS_127SW_IPHSURVEY020_RIDER 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE16 FUV Count vs Time Typical FUV Count vs Time EUV Count vs Time Typical EUV Count vs Time

17. EUVFUV Data Volume Reduction Tests in S59 to repeat issue documented in ISA Z89939. –Also test on some setup Bob wanted to use in XXM but are affected by ISA Z89939. Tests show that we have a problem when doing some type of spectral windowing. –Need more time to analyze these tests. 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE17

18. SSR Allocation Reduction Use correct data rate: –EUFUV scans use 4862 bps, have 5032 bps allocated (with HDAC). Estimate the turns time when possible: –EUVFUV “template” allocate 20 minutes at both ends of a request. Indicate in CIMS where you want data to be taken (e.g., systems scan or some icylon/icymap). 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE18

19. SSR Allocation Reduction But… because of the requirement that we synchronize data acquisition with S/C movement a lot of data potential is lost: –UVIS does not return partial integration. –There is some overhead associated with synchronization. –Both situations lead to overestimating the SSR allocation. 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE19

20. SSR allocation notes On the S/C the SSR allocation is done per observation period (not at the CIMS request level): –From time to time we reduce UVIS SSR allocation when too much of the allocation is unused (in % or in absolute value). We select the request(s) where this reduction is easier on us when updating CIMS. –We re-allocate data between requests in the same observation period. No update to CIMS 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE20

21. New in XXM New power modes (ECR 109282) –The new standard operating mode for UVIS is called “no_hdac_mod” (9.4 W – as measured by the S/C). If need to modulate the HDAC filaments ask for the “on” mode (14.6 W). Still need to work with SCO on a mechanism to indicate in the PEF that we are modulating HDAC. –New “Downlink mode” (7.1 W) for IPHSURVEY. –Initial implementation for the new modes is 11/2010 (?) 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE21

22. New in XXM Increased SSR library allocation for UVIS IEB starting in S65. Both SOPCs are running Solaris 10. 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE22

23. XXM Preparation Manual procedures and checklists have been scrubbed. Standard IEB contents has been updated. –e.g., EUVFUV scan at 1 kbps vs 5 kbps Current scripts have been updated. – e.g., “PIE” vs “PRIME” New scripts have been developed. 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE23

24. Rbot: Workload Impact The impact of Rbot on the ops team workload is highly variable: –S60: 2 requests out of 9 had to be modified. –S61: 3 requests out of 9. –S62: Nothing. –S63: 4 requests out of 12. –S64: Don’t know yet. 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE24

25. 06/28/10UVIS TEAM MEETING OPERATIONS UPDATE Notes and Reminders Use UVIS_SOLAR_OFF to Sun in CIMS for all solar occultation instead of ISS_NAC to Sun (-20.0, 0.0, -0.11 deg) offset. HDAC modulation is a non-standard power mode. Before requesting sponge bits let us know what you want as we may have a good understanding of instrument SSR loading. The list of ring occultations that contain an atmospheric occultation is on the team web site at http://lasp.colorado.edu/cassini/team-site/archive/docs/pdf/Atmospheric_Occ.pdf http://lasp.colorado.edu/cassini/team-site/archive/docs/pdf/Atmospheric_Occ.pdf The list of all the tour calibrations is on the team web site at http://lasp.colorado.edu/cassini/team-site/archive/docs/pdf/UVIS_Tour_Calibration.pdf http://lasp.colorado.edu/cassini/team-site/archive/docs/pdf/UVIS_Tour_Calibration.pdf The UVIS PEFs are on the team web site at http://lasp.colorado.edu/cassini/team-site/operations_planning/planning_info/ http://lasp.colorado.edu/cassini/team-site/operations_planning/planning_info/ 25