Sham2 - sequence for darks, canopus, encounter slewing test ------------------------------------------------------------ ----------------------------------------------------------------- Proposed sequence for Shamtilly2 ----------------------------------------------------------------- 1) Author / phone Scott Murchie / 301-953-6235 2) Priority High 3) Submittal Date 4) Execution Window 5) SDC Data Rqd Date flexible 6) Recorder required 53 Mb? 7) Request Description: Shamtilly revision 8) Critical event? yes 9) Similar previous event? no 10) Special instructions see below Main purpose: - calibrate spacecraft maneuvering for Mathilde - test plan for coadding Mathilde opnav images - verify knowledege of MSI boresight Additional results w/o extra maneuvering: - additional data on filter wheel behavior - further data on imager characteristics needed for Mathilde opnav and image acquisition (point spread function of clear filter; distortion through color filters) - fuctionality of some image compression software Details of plan (developed by G. Heyler, A. Harch, S.E. Hawkins, S. Murchie) TIMELINE t0 =Instrument Power-on + 5.5 hours = 1997 day 15, 0700 GMT = 28721789 Ground MET = -93416400 UT = -93416338 TDB t0 - Slew to dark sky region near Canopus, settle. (ra = 99.0, dec=-54.35, sun angle = 10.86). t0+570 - MSI SEQ 1 Acquire 2 images of dark sky, filter 7, 10 and 999 ms exposures. Fast + DPCM compression. t0+600 - Slew to Canopus, settle. t0+990 - MSI SEQ 2 Acquire 8 20-ms exposures, filter 0, 1 second apart. Fast + DPCM compression. t0+1170 - MSI SEQ 3 Acquire 1 20-ms exposure, filter 0. Rice + DPCM compression. t0+1200 - Slew to fake asteroid nadir, having loaded orbit, new gains, sun angle = 10.1 for next 2000 sec. t0+1700 - Slew to 10.3 deg off nadir upstream t0+2100 - Begin scan patterm to 7.3 deg downstream t0+2145 - MSI SEQ 5 Acquire 8 999 ms exposures, filter 0, 1 sec apart. No time for compression. t0+2153 - MSI SEQ 5 Acquire 8 999 ms exposures, filter 0, 1 sec apart. No time for compression. t0+2270 - Arrive at 192 km downstream. Begin upstream scan. t0+2280 - MSI SEQ 6 Acquire 8 999 ms exposures, filter 0, 1 sec apart. Fast + DPCM compression. t0+2370 - stop upstream scan at 192 km upstream t0+3200 - Slew to Alcyone, settle. (ra=56.87, dec=24.105, sun angle=7.63 t0+4280 - MSI SEQ 7 Acquire 8 999 ms exposures, filter 0, 1 sec apart. t0+4460 - MSI SEQ 8 Acquire 4 999-ms exposures, filter 1, 1 sec apart. t0+4640 - MSI SEQ 9 Acquire 4 999-ms exposures, filter 5, 1 sec apart. t0+4820 - MSI SEQ 10 Acquire 4 999-ms exposures, filter 3, 1 sec apart. t0+5000 - Replace orbit, gains. Return to earth-safe attitude. IMAGE DEFINITIONS # # # Two Dark Frames -- Execute 5.5 hrs after instrument power-on. # 10 and 999 ms exposure times, filter 7, # FAST+DPCM compression. # CMDLOAD SS_DATA_LOAD 30 MSI CMD MS_DIA_SEQ 1 2 NONE 1 NONE ON FAST 16 MAN \ 10 999 0 0 0 0 0 0 7 7 0 0 0 0 0 0 # # # Eight 20-ms exposures through filter 0, FAST+DPCM # compression. For use at Canopus, with star at # best-known boresight of MSI: # CMDLOAD SS_DATA_LOAD 30 MSI CMD MS_DIA_SEQ 2 8 NONE 1 NONE ON FAST 16 MAN \ 20 20 20 20 20 20 20 20 0 0 0 0 0 0 0 0 # # # One 20 ms exposure through filter 0 using RICE+DPCM # compression. # CMDLOAD SS_DATA_LOAD 30 MSI CMD MS_DIA_SEQ 3 1 NONE 1 NONE ON RICE 16 MAN \ 20 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 # # # Eight 999-ms exposures, 1 sec apart, filter 0, no compression. # This is for use TWICE (at the first target) during the practice # Mathilde slew; Insufficient time for image compression. # CMDLOAD SS_DATA_LOAD 30 MSI CMD MS_DIA_SEQ 5 8 NONE 1 NONE OFF NONE 16 MAN \ 999 999 999 999 999 999 999 999 0 0 0 0 0 0 0 0 # # # Eight 999-ms exposures, 1 sec apart, filter 0, # FAST+DPCM compression. This is for use ONCE (at the # second target) during the practice Mathilde # slew; enough time for compression. # CMDLOAD SS_DATA_LOAD 30 MSI CMD MS_DIA_SEQ 6 8 NONE 1 NONE ON FAST 16 MAN \ 999 999 999 999 999 999 999 999 0 0 0 0 0 0 0 0 # # # Eight 999-ms exposures through filter 0, 1 sec apart, # FAST+DPCM compression. For use at star cluster. # CMDLOAD SS_DATA_LOAD 30 MSI CMD MS_DIA_SEQ 7 8 NONE 1 NONE ON FAST 16 MAN \ 999 999 999 999 999 999 999 999 0 0 0 0 0 0 0 0 # # # Four 999-ms exposures through filter 1, 1 sec # apart. Fast + DPCM compression. For use at star cluster. # CMDLOAD SS_DATA_LOAD 30 MSI CMD MS_DIA_SEQ 8 4 NONE 1 NONE ON FAST 16 MAN \ 999 999 999 999 0 0 0 0 1 1 1 1 0 0 0 0 # # # Four 999-ms exposures through filter 5, 1 sec # apart. Fast + DPCM compression. For use at star cluster. # CMDLOAD SS_DATA_LOAD 30 MSI CMD MS_DIA_SEQ 9 4 NONE 1 NONE ON FAST 16 MAN \ 999 999 999 999 0 0 0 0 5 5 5 5 0 0 0 0 # # # Four 999-ms exposures through filter 3, 1 sec # apart. Fast + DPCM compression. For use at star cluster. # CMDLOAD SS_DATA_LOAD 30 MSI CMD MS_DIA_SEQ 10 4 NONE 1 NONE ON FAST 16 MAN \ 999 999 999 999 0 0 0 0 3 3 3 3 0 0 0 0 # # # Entire observation: (2+8+1+8+2*8+8+4+4+4)=55 frames # # # #****************************************************************** # SEQUENCE TEMPLATE * ##***************************************************************** # * # Image Sequence ID = 1-30 * # Images in Sequence = 1-8 * # Repeating Sequence = NONE * # Time Between Images = 1-255 (sec) * # Lossy Table = NONE/TABLE1-TABLE7 * # Differential PCM = ON/OFF * # Lossless Algorithmn = NONE/FAST/RICE * # Pixels per Block = 1-16 * # Exposure Mode = MAN/AUTO * # * # Image #1 Exposure Time = 1 ms Filter Wheel Position = 0 * # Image #2 Exposure Time = 10 ms Filter Wheel Position = 1 * # Image #3 Exposure Time = 50 ms Filter Wheel Position = 2 * # Image #4 Exposure Time = 100 ms Filter Wheel Position = 3 * # Image #5 Exposure Time = 500 ms Filter Wheel Position = 4 * # Image #6 Exposure Time = 750 ms Filter Wheel Position = 5 * # Image #7 Exposure Time = 900 ms Filter Wheel Position = 6 * # Image #8 Exposure Time = 999 ms Filter Wheel Position = 7 * # * #****************************************************************** # # CMDLOAD SS_DATA_LOAD 30 MSI # CMD MS_DIA_SEQ 1 8 NONE 1 NONE ON FAST 16 MAN \ # 1 10 50 100 500 750 900 999 0 1 2 3 4 5 6 7 # #****************************************************************** # # Gene, There's only 6.5 minutes for Canopus slew and settling before imaging starts. Is that enough? The CHANGES I made are: 1) Please use Ra=99.0 instead of 97.52 for dark sky near Canopus if it's okay. 2) Changed sequence end time 'to replace orbit, gains, etc' from t0+4200 to t0+5000. Didn't look like there was enough time settling and to do the imaging (MSI SEQ's 7,8,9, and 10). We want to be very still for these images. Talk to you soon. I'm going to go through this with Scott tomorrow (I'm meeting him).Thanks again for all the help with this. I'll be at 510 525-7464 in the eves and I'll check my email if you have questions. Ann