APACHE POINT OBSERVATORY SDSS 2.5M OBSERVING LOG Sunday December 23, 2001 (MJD 52267) ---=== OBSERVING TEAM ===--- Swing: Steph Snedden (APO) Night: Jurek Krzesinski (APO), Pete Newman (APO) Support: French Leger (FNAL), Carlos Gonzales (FNAL) ---=== OBSERVING PLAN ===--- Short pointing model per JEG's request, then science with usual priorities. ---=== OBSERVING SUMMARY ===--- Closed by weather before we could obtain any observations. ---=== OBSERVING LOG ===--- Variable high clouds at sunset, forecast to continue, so we use this opportunity to take a a short set of poining observations to check the current model, per JEG's request in the survey operations phonecon on 2001/12/20. We were delayed in opening to 01:20 UT (about 35m after sunset) following more work by French and Carlos on secondary mirror actuator A. At handover, the secondary was moving very well, but a focus change during set-up for the pointing model observations triggered the 'slow-motion' failure on actuator A again. We spent some time trying to move just the A actuator to see if would free itself, then reverted to homing all actuators. Again, we see the behavior that on the first one or two attempts to home, actuator A moves very slowly until the controller times out, then on subsequent moves, it runs at normal speed. Is this expected? Does this offer any clues to what component is failing? After homing, the actuator again ran ok (but for how long?). We wonder if sluggish motion of the A actuator might have been occuring for a long time. If this has occurred unnotived during pointing model observations, then it would have introduced errors in position that would be systematically along one direction with respect to the telescope axes. We have noticed elongated images in pointing observations in the past, but attributed them to delays in the rotator arriving at the desired position. Perhaps the problem has in fact been the actuator. Thanks to Steph for raising this question. Pointing model data: We will take particular care during these observations to check both the secondary actuator positions are tracking the commanded positions, and that the fiducial errors are not growing excessive. We focused (FWHM ~ 10 pixels = 1.5 arcsec) and checked the centering of the engineering camera to be 9.5 pixels radial error (~1.4 arcsec). We then closed at about 03:30 UT due to increasing clouds that had preciptated to the west, and saw snow fall about 10:20 UT, at which point we give up for the night. ---=== IMAGING RUN SUMMARY ===--- Run Stripe Flavor Lambda Last Begin End Frame Comments ------------------------------------------------------------------ 2840 100 O bias 140.82 159.34 50 doghouse bias IGNORE ---=== IMAGING RUN DETAILS ===--- ---=== SKIPPY RESULTS ===--- Run Frame nFrames stars muErr muRms nuErr nuRms rot --------------------------------------------------------------- ---=== LTMATCH RESULTS ===--- Run Field nFields nGood rowMean rowSig colMean colSig rot --------------------------------------------------------------- ---=== SPECTROSCOPY DATA SUMMARY ===--- UT Exp Time flavor comment (S/N)^2 totals ========================================== b1 r1 b2 r2 ----- sequence 12410, plate -9999 ------- 23:06 12410 0.0 bias ---=== TELESCOPE OFFSETS AND SCALE I ===--- Time Instrument getclock Az Alt Rot Scale ------------------------------------------------------------------------------ ---=== TELESCOPE OFFSETS AND SCALE II ===--- ---=== DATA TAPE SUMMARY ===--- Goes: none Stays: none ---=== FOCUS LOG ===--- setmir piston Temp Wind Time Inst scale M1 M2 Foc Az Alt (C) MPH Dir filt fwhm ------------------------------------------------------------------------------ 03:29 engcam 1.00000 0 -2343 -100 121 30.0 -7.9 16 80 -- 1.5 ---=== WEATHER LOG ===--- Wind Time Temp F Dewp F MPH Direction Dust DIMM Sky 15:59 28 4 4 212 (SSW) 102 - Variable cloud 16:30 26 4 0 229 (SW) 108 - " 17:02 26 3 7 91 (E) 111 - " 17:34 25 5 8 153 (SSE) 117 - " 18:10 24 -2 16 157 (SSE) 110 - " 18:43 24 -10 17 157 (SSE) 74 - " 19:15 24 -9 16 167 (SSE) 106 - " 19:51 25 -1 10 177 (S) 114 - " 20:23 25 0 12 173 (S) 121 - Overcast 20:56 24 0 15 141 (SE) 126 - " 21:32 24 1 16 131 (SE) 140 - " 22:04 24 2 13 139 (SE) 138 - " 22:36 24 2 10 176 (S) 150 - " 23:08 24 2 14 141 (SE) 142 - " 23:41 24 1 16 145 (SE) 153 - " 00:13 23 2 13 128 (SE) 167 - " 00:45 23 4 14 127 (SE) 169 - " 01:17 20 8 11 112 (ESE) 245 - " 01:50 19 9 12 87 (E) 389 - " 02:22 18 9 13 83 (E) 397 - " 02:54 18 8 14 109 (ESE) 353 - " 03:26 17 9 16 87 (E) 428 - Light snow ---=== TELESCOPE STATUS ===--- UT 00:00 Fans on, doors opened. 01:40 Enclosure off. 03:30 Enclosure on. 10:20 Fans off (snow falling). Status at end of night 03:30 MST / 10:30 UT: Telescope stowed at: 30 deg Instrument mounted: Engineering camera Counterweights at: 125 Autofill systems: On 180L LN2 dewar weights: Spectro 67 lb Imager 133 lb Interlocks bypassed: Slip detection, building motion, roll-up door kick-back. IR Sky Camera LN2 dewar was filled at ~ 00:00, 04:30 and 08:30 UT. Closed at 10:30:UT. ---=== SOFTWARE USED ===--- IOP/SOP: v3_64_3a Watcher: v2_13_2 MCP: v5_8_5 TPM: v2_4_5 AstroDa: v14_40 TCC: 2.5.5 sdssProcedures: v1_34 ---=== MIRROR NUMBERS ===--- Not obtained ---=== PROBLEMS IN DETAIL ===---