RTS2-F MODUS OPERANDI
 
Created 06/26/12 EF
Updated 11/07/12 EF

Each time it is enabled to operate (mode switched to ON), RTS2-F
follows a prescribed daily sequence with appropriate waiting periods
between activities (e.g., between dome and sky flats). The core of the
system is its database of targets, built from user catalogs. The
database and the catalogs are described in the following
sections. RTS2-F classifies time into 6 states: day, evening
(twilight), dusk, night, dawn, morning (twilight); after morning
twilight the state cycles back to day. RTS2-F records each command it
executes in files labeled /home/observer/ROBOT/LOGS/run-YYMMDD (in any
xterm, SHOWlogs [YYMMDD] prints today's or the YYMMDD log).

Start RTS2-F by first changing the system mode to ON with the
GOweather GUI or the MONrobot tool, or from RTS2-G, and then typing
GOrobot in the Telshell command window. The command GOrobot invokes a
script that performs the sequence that follows.

1)  Anytime: Observers enter targets into the catalogs and/or the queues.

2) Anytime: Once started with GOrobot RTS2-F continually tests for an
  on/off flag indicating that the command STOProbot has been
  issued. If it finds the flag on, RTS2-F stops. RTS2-F may also be
  stopped in an emergency by changing the system mode to OFF with
  GOweather, MONrobot or RTS2-G. If this change occurs, RTS2-F closes the
  dome slit, stops exposing, stows the telescope and closes the mirror
  covers, in that order. Such a change of mode may also be triggered
  automatically by adverse weather, such as high wind or humidity.

3) Afternoon: about 2 hours before dusk, with the dome slit closed
  acquire standard biases and dome flats (number of biases and default
  BVri filters listed in /home/observer/RTS2-F/FLATS/DOMEFILT). This
  step is performed regardless of weather conditions, as the dome slit
  remains closed. Skip this step with "GOrobot -D."

4) Afternoon: the Keplercam dewar is filled automatically at 5-6
   pm and 7-7:30 am (these times vary seasonally; command ftime shows them).

5)  Dusk: open the dome slit if the weather allows, and wait until it
  is sufficiently dark for sky flats.

6) Dusk: Acquire sky flats; exposures are adjusted to obtain mean
  levels of about 15K counts. The files
  /home/observer/ROBOT/FLATS/SKYFILT_X with X=E,M contain the filters
  and exposure times for sky flats. The defaults are filters u and i.
  Skip evening (morning) sky flats with "GOrobot -e" ( "GOrobot -m".)

7)  Dusk: after sky flats, reference the telescope position (find
  zenith).  Skip this step with "GOrobot -R." 

8)  Dusk: measure the FWHM of stars at different telescope focus values
  and adjust focus to minimize the FWHM.  Skip this step with 
  "GOrobot -F."

9) Night: if "GOrobot -P", fix the pointing using astrometry on a
   10-sec exposure taken near zenith. Offsets are calculated and
   applied, and "tele ref" is run.

10) Night: observe accessible targets from the RTS2-F database or use
  lists specified in the calibration, manual or plan queues. Inclement
  weather may cause the telescope to shut down. Adjust focus after
  each exposure as a function of temperature, as described below.

11) Night: if the robot stops for any reason and is restarted later,
  it checks the status of the slit and mirror covers, and opens them
  if necessary.  It then continues observations as in the previous
  step.

12) Dawn: about 20 minutes after the onset, if evening sky flats were
  not collected, acquire sky flats.

13) Morning: stow the telescope and close the dome slit.

14) Morning: if there were no dome flats from the beginning of the night,
  acquire standard biases and dome flats about 50 min before the LN2 fill. 

15) Day: at about 9am MST, software running at the TDC in Cambridge
  automatically transfers the night's data to the archive in
  Cambridge. The process takes up to 3 hours, depending on the
  number of files.