OSIRIS Hieroglyph The OSIRIS User's Manual
[Contents]		 



  
    

      
      
Observing Setup

      		
      


      		
    

  


This section discusses the following topics:


Unix Workstation Startup

OSIRIS is operated using the Prospero Interactive Data
Acquisition
Program. Details for how to use Prospero for observing are
described in detail in the Prospero Observer's Guide (available
in
the control room or on-line from the anonymous ftp sites, see Appendix C). This section describes the setup
procedures you need to follow on the first night of your observing run.

OSIRIS observers login to the main observing console using vncviewer at soaric2 (vncviewer :9, or
vncviewer soaric2: remotely). The SOAR support scientist will
provide you with the current password. This session should be served by
a vnc server started as user "observer."






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Starting Prospero

Prospero should startup automatically when you log back in after
completing the first-night initialization process
described above. If for any reason you need to restart Prospero
during an observing run, use the workstation menu (left mouse button)
and
select the option labeled:


  
Restart Prospero



from the menu.

When Prospero is started, you should be presented with
two
windows: an xterm labeled "Prospero Command", and a
second
window labeled "Prospero Status" located immediately
above
the command window. The status window will be blank until you have
connected Prospero to the data-taking PCs and started an OSIRIS
observing session (type "startup"). While you may make either an icon,
closing either
window will quit the Prospero program, requiring you restart
as described above.



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Other Programs

Before Prospero can be connected to the data-taking PCs, you
need to
make sure that two other auxiliary programs are running: isis, TCS
agent, and
caliban.

isis:

The isis program acts as the main server in the client-server
architecture of the OSIRIS data taking system. When starting the system
from scratch, always start isis first.



caliban:

The caliban program is a unix daemon responsible for
transferring
OSIRIS images in FITS format from the data-taking PCs to the
Sparcstation
data disks. Before starting caliban, the data-taking PC system must be
turned on and ready to go.

caliban is started automatically upon login to the
workstation after
completing the first-night initialization process
described above. If caliban is not running (or has crashed), it needs
to be restarted from the workstation menu (left mouse button) by
selecting the option labeled: 



  
Restart Caliban



from the menu.
caliban will start up as an icon labeled "Caliban" and
automatically connect to the WC and mount the two data transfer
disks. Normally caliban is left as an icon to save on
workstation
screen space, and should only need to be opened if you need to interact
directly with caliban to investigate problems. Typing the "?" in the
caliban window will give a list of interactive commands. Be
aware
that careless use of the caliban command window could shutdown the data
transfer system and lead to loss of data (if you don't have a good
reason
to mess with it, don't!).



The caliban setup at CTIO is also responsible for archiving
all
data taken with OSIRIS via the Save-the-Bits
Archive. 


Automatic observation logging is available via caliban using
the
AUTOLOG option. See the description of autologging in Appendix
D
(Observing Tools) of the manual.




tcs agent:




This program connects the OSIRIS data taking system to the SOAR TCS
so that information can be retrieved from the TCS and commands can be
sent to it (e.g. offsets, focus, guider control). Type help in the tcs
agent windo to see a summary of avaialble commands.






Additional Tools & Documentation:


IRAF is custom configured especially to work with OSIRIS data. It
assumes all data are in FITS
format with the .fits file extension. You can start
IRAF
in an xGTerm from the workstation Programs menu.


Use DS9 for image display.




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Nightly Setup Checklist



Nightly Initialization

At the beginning of each night, after starting the data-taking system
from
the Prospero console using the STARTUP
command,
you need to do the nightly run initialization. This is performed via
the
RUNINIT.

RUNINIT performs the following functions:



In addition to setting these defaults, RUNINIT also
updates the initialization/restart files used by all data-taking
computer
subsystems. This ensures that if you need to restart the system for any
reason during the night you will quickly recover the appropriate
defaults
for filenames, data directories, etc. This can save you a great deal of
time and trouble on crash recovery.



Check the Data Disks for Space

All computers and programs behave badly if you fill a disk. In general
there are a few gigabytes of disk space available to you during the
run,
but if you fill up a disk in the middle of a critical observation, the
data-taking system will start choking, and you will have to stop and
fix
things, almost always at the most inopportune time possible.

Save yourself potential trouble by checking the status of the data
disks at
the start of each night (in addition to keeping close tabs on things
throughout the night). Select as your starting data disk (see
RUNINIT above) the disk with the most free space
among
those you have access to. Type "df" at a unix prompt and see how much
space remains on /data/observer. 






Focusing

Both the internal optics and the telescope should be in focus for the
most
optimal images.

The internal optics can be focused by inserting one of the
spectroscopic slits into the beam and then running the camera focus
through
a range of values. Steps of 50-100 in the camera focus are
appropriate. Approximate values (Dec 1999) are "camfocus
400" for the f/2.8 camera, "camfocus
650" for the f/7 camera, and
"camfocus 0" for the pupil viewing Silicon
lens. These values can change approximately +/- 100 from run to run,
but should be reliable once a best focus is determined on any
particular run. Use the command focuscam from the Prospero
command window to automatically take a set of camera focus data.



The telescope can then be focussed in the normal manner. We
generally
find a rough focus by starting "movie" mode on the array (which reads
out
the array continuously) and then running the telescope focus in and out
until the image looks good, then taking a series of images at different
focus settings. There is no analog to the CCD command that reads out a
single frame with multiple images of a star at various telescope foci.




See the observing notes bullet on the main page for more information
on focusing.




Pupil Mask Alignment

In imaging mode, the silicon lens camera images the telescope pupil
onto
the detector array. There is also a cold pupil mask in the dewar that
can
be moved (using the "xpupil" and "ypupil" commands) to align the mask
with
the pupil to reject the thermal emission from the telescope secondary
support and mirror cell. The procedure for aligning the mask is to
insert
the Silicon lens and the K filter into the beam (see the list of filter
wheel populations for OSIRIS), select
CAMERA 2 (Pupil Viewing Camera), and set the camera
focus
to 0 ("camfocus 0").



A short exposure against the night sky will produce a good image of
the pupil.
Here is an example of what a properly aligned
pupil mask should look like on the 1.5m
and 4m. The pupil mask is matched to the 4m
and does not cover the
entire central obstruction on the 1.5m.
Move "xpupil" and "ypupil"
around until the dark areas obscure as much of the bright as possible.
Default values are xpupil=??, ypupil=??.




Note that this procedure need only be done at most once per run,
but
it is a good idea to check that the pupil mask is correctly aligned
before
you start observing for the night.



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Updated: 2005 June 29