Subject: 3.5m Night Log 20180426
From: cgray@apo.nmsu.edu
Date: Fri, 27 Apr 2018 12:55:03 +0000 (UTC)
                      Apache Point Observatory
                      3.5m Telescope Night Log
                      Thursday, April 26, 2018
                                                           ACTUAL
 ASTRONOMER      OBSERVER(S)            INSTRUMENT     START  FINISH
--------------------------------------------------------------------
T.Murphy          R.McMillan            APOLLO         --:--   --:--
M.Klaene          R.McMillan, C.Gray    arctic         --:--   --:--
   INST       SCHEDULED     WEATH     EQUIP      OBS     NOT USED
 I/ROW/DN   START  FINISH   D    B    D    B    D    B    D    B
 ----------------------------------------------------------------
AP01/R     19:50   20:50   0.0  1.0   0    0    0    0    0    0
EN01/W     20:50   06:12   0.9  8.4   0    0    0    0    0    0
note: scheduled times listed include instrument change time
              ------------- ACTIVITY LOG --------------
Observing Specialist: C.Gray
gcam needed a restart at checkout.  Things were super windy.  We tried to open for Apollo before sunset but the wind was from the east and we closed when it gusted to 40 mph.
The night was a total wash. When it was gusting near 50 mph it was dusty and while it was dusty and windy it was cloudy.  It didn't rain, which was rather disappointing. We were not able to do anything on sky for engineering but we did zero the rotator (-0.15) and zeroed the axes.
Russet tested dacm at various current temps and found that "lower cooler" current (warmer) did seem to show better dcam behavior, but it still wasn't good.
We did LOTS of ARCTIC filter position tests. The short-short version is:
---Keep filter wheel the same, change rotator position---
 No obsrvable offset.
----Keep rotator position and change filters---
Immediate offsets observed in unbalanced wheels (ones with empty filter slots).
  - Rotator 0 - slight upward offset
  - Rotation 90 - large downward offset
  - Rotation 180 - slight upward offset
  - Roation 270 - large upward offset
Balanced wheels (all filter slots filled) showed much less offset but offset direction was the same as an unbalanced wheel.  Fully balanced wheel (all filters the same size) showed no offset (but filters were 5" and it was difficult to see small offsets).  This suggests that gravity is an issue when rotating the wheel and is leading to misalignments of the wheel.
When homing the filter wheel I could not home the wheel on the first try in any position but it took many attempts to home on any rotation position that wasn't 0 suggesting there's a homing issue when the instrument is upside down.
We tested the filter wheel control using Conner's new code and the results were much better!  Even with an unbalanced filter wheel there was very little offset.  Offset direction was the same as previous tests but it took nearly 200 filter changes in order to observe the offset. The only issue is the wheel would not home properly and I had to reset and connect the controller in order to home.
                    ------- FAILURE LOG -------
PROG   INST   FAILURE MODE     TIME
    (SEDFNVOG)   TI/SHU    START  FINISH  DESCRIPTION
----------------------------------------------------------------------
            ---------------- FOCUS LOG ---------------
Time  Instrument  Focus     Az  El  Temp Strc Prim  Sec  Air  filt  FWHM
--------------------------------------------------------------------------
               ------------- WEATHER LOG ----------------
                                   Wind                      Precip.or
     Time   Temp F Dewp F  MPH  Direction    Dust    Sky    Conditions
    ------------------------------------------------------------------
     16:00    58    14     10   309   (NW)    702   cloudy     none
     17:00    57    13      3   307   (NW)    864   cloudy     none
     18:00    53    18     16    76  (ENE)   1186   cloudy     none
     19:00    49    18     17    86    (E)   1189   cloudy     none
     20:00    46    18     16    68  (ENE)   1472   cloudy     none
     21:00    44    18      9   103  (ESE)   2496   cloudy     dust
     22:00    42    19     30    76  (ENE)   6060   cloudy     dust
     23:00    40    20     25    71  (ENE)   5112   cloudy     dust
     00:00    38    20     31    75  (ENE)   4055   cloudy     dust
     01:00    37    21     31    69  (ENE)   3236   cloudy     dust
     02:00    35    20     25    73  (ENE)   2569   cloudy     dust
     03:00    34    20     24    75  (ENE)   2078   cloudy     none
     04:00    33    20     20    73  (ENE)   1835   cloudy     none
     05:00    33    21     15    75  (ENE)   1831 mstly cldy   none
     06:00    33    20     16    76  (ENE)   1856 mstly cldy   none
     Note: the wind was coming from the azimuth listed.
     The convention used is north=0 degrees, east=90 degrees.
     The dust count is particles > 1u per 0.1 cubic feet.
                          TELESCOPE STATUS
    Telescope drives operational. Current TCC version: 1.2.4
    Current TUI version: 2.6.0