Date: Fri, 18 Feb 2000 02:39:04 -0700 From: Dan Long Subject: obslog 000217 (MJD 51592) THURSDAY FEBRUARY 17, 2000 APACHE POINT OBSERVATORY SDSS 2.5M OBSERVING LOG (MJD 51592) Observing team: Dan Long (APO) Scot Kleinman (APO) Atsuko Kleinman (APO) Brian Laubscher -- PT (LANL) Visitors: Ron Rechenmacher (FNAL) Plan for tonight: Observer training. Trying again for practice with the imager since we did not get on the sky last night. Opening was delayed until 22:30 due to dust, clouds, and wind. In the mean time, we put the imager on and ran bias drifts to exercise the archiver. When we eventually did open we did get some on sky imaging practice in less than ideal conditions. Endnight was also successful. This evening I discovered it is possible to have the brakes not come on when an axis is out of closed loop even when the monitor is on ( PR 851 ). The following sequence will cause the error. I am not sure every step is necessary, but they will cause the brakes not to come on and the altitude can drift since the windscreen will be active. Initial conditions: 1) Amplifiers on 2) Stop button in 3) Interlocks OK motion except for brakes and stop button 1) Perform an altitude amplifier reset from the Menu 2) Clear the altitude brake 3) Hit "s" in the Menu 4) Hit "h" in the Menu 5) Pull out the last stop button 6) Issue another altitude amplifier reset from the Menu At this point the windscreen will become active, the brake will be off, and the altitude will not be in closed loop ( * A * on the Menu status ). If the altitude axis is out of balance, the telescope will drift. When we set up, we noticed the imager focus, aside from having miserable fwhm, was nearly 800 microns positive from what it had been on recent nights. This is probably due to the telescope not having a chance to equilibrate earlier in the night because we couldn't run the fans with the dust counts being high. Indeed it dropped throughout the run nearly 300 microns back toward the focus of recent nights. Imaging Runs: ------------- 1160: bias run, unknown length ( daytime ) 1161: bias run, unknown length ( daytime ) 1162: long bias run ( ~250 frames ) 1163: Setup on stripe 10 S 1164: Pretend science run on 10 S -60 ( decidedly not survey quality ) Seeing 2" to 3", bright moon, and variable high clouds. (~200 frames ) Spectroscopy: ------------- None tonight. EndNight: Tapes 1 2 ID1 JL1895 JL1928 ID2 JL1924 JL1929 ID3 JL1925 JL1930 ID4 JL1896 JL1931 ID5 JL1926 JL1934 ID6 JL1927 JL1935 Gang JL1933 JL1957 Endnight -doImager completed successfully. More "great rejoicing" was had by all. The tapes are on the shelf ready to be shipped. Fresh tapes are in the drives. MIRROR NUMBERS Primary: setmir( cmd ): 0 -3.9 3.9 213.5 213.5 galil( act ): 4850 -2350 100 -9500 50 -100 linear gauges 1 = Axial A = 1.9315 2 = Axial B = 0.5570 3 = Axial C = 0.5570 4 = Transverse = 0.4080 5 = East Lateral = 1.8975 6 = West Lateral = 0.3985 Secondary: ( inst=imager focus=607 alt=57.0 deg T=-1.2 C) setmir( cmd ): 355.55 5 -5 50 -54.54 setmir( act ): 355.52 5.01 -5.01 49.95 -54.13 galil ( act ): 459967 447066 436774 -750 -5450 linear gauges 1 = Axial A = -0.407 2 = Axial B = -0.383 3 = Axial C = -0.382 4 = Transverse = 0.030 STATUS Software: sop v3_8_5 watcher v2_6_1 iop v3_8_5 mcp v3_1_1 Spectro dewars were filled this afternoon at 15:00 and again when we closed at 02:00. The imager dewar was replaced at 02:00. No interlocks were/are bypassed tonight. The telescope is currently empty. Counterweights fully down. WEATHER Skies tonight were variably cloudy. The temperature started in the upper 30s at sunset and dropped to the upper 20s by 01:00. Winds were out of the west at 25 to 45 MPH early in the evening, slowly dropping to 15 to 30 after about 22:30 and shifting to the NW. Humidity ranged from 30% to 50%. Dust counts were over 4000 at sunset and dropped to under 2000 an hour or so later. PROBLEMS IN DETAIL None to report!