Automatic Observation Logging (AutoLog)
The caliban daemon is responsible for transferring all images from
the data-taking PCs and writing them as FITS format images on the
Sparcstation disks. After an image is written, at least two subsequent
actions are performed on the newly written data:
- The FITS file is submitted to the Save-The-Bits auto-archiving queue.
- The FITS file header is sniffed by AutoLog and entered into
a running observing log for the night.
Of these two, automatic archiving is always enabled, and can only be
disabled by the support scientist.
Autologging is currently not enabled by default, but can be started by the
observer. AutoLogs are generated in ASCII text format, and can be easily
read by any screen editor or imported into a spreadsheet program (e.g.,
Excel or Lotus). At present there is no option for generating logs in TeX
or LaTeX format (we tried, it was ugly, and since nobody has been pounding
down our doors for it, it hasn't been given high priority).
This document describes how to use AutoLogging with OSIRIS. If we find it
being widely used it may be enabled by default.
You can instruct caliban to enable AutoLogging from either the
Prospero command prompt or in the caliban command window.
From Prospero:
At the Prospero prompt, type the commmand:
CB +AUTOLOG
From caliban:
In the caliban command window (usually started as an icon),
type the commmand:
+autolog
Either command will enable autologging for the current session. If
caliban has to be restarted, the default condition is autologging
disabled and you will have to re-enable autologging by hand after
recovering from a crash.
Once enabled, the next file written will start the log for the current observing day.
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You can instruct caliban to disable AutoLogging from either the
Prospero command prompt or in the caliban command window.
From Prospero:
At the Prospero prompt, type the commmand:
CB -AUTOLOG
From caliban:
In the caliban command window (usually started as an icon),
type the commmand:
-autolog
Either command will diseable autologging for the current session. If
caliban has to be restarted, the default condition is autologging
disabled, so you will not have to disable logging again after
recovering from a crash.
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AutoLog produces an ASCII text files with names of the form:
ccyymmdd.log
where ccyymmdd is the date of the Observing
Day on which the image was written to disk.
AutoLog files are written into the Logs directory in the
osiris observing account:
/data/Logs/ccyymmdd.log
The log is owned by the "osiris" user since the AutoLog program is triggered
by the caliban daemon running on the osiris observing account.
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The "Observing Day" used by AutoLog begins at noon local time on the date
of the start of the night, and ends at 1159 local time the following day.
Defined in this way, all afternoon (and morning) calibration or engineering
check-out data associated with a given night of observing will be in the
same autolog file.
Example:
An night of observing runs from the evening of 1999 February 16 to the
morning of 1999 Feb 17. The "observing day" used by the AutoLogger will be
1999 Feb 16, and the log file will be named 19990216.log.
A new logfile is started at noon on each observing day.
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When the AutoLog program is triggered by the caliban daemon, the
FITS header of the file is sniffed for a set of predefined header cards
that contain all of the information in the OSIRIS format file (osiris.fmt).
The information entered in the log is currently fixed by the support
scientists and is not user-defined (if there are format errors in the log
format file, it screws up the whole autologging process. However, you can
run the base program yourself with a custom format file after the
night is done as described below).
The first line of the log is a header describing the entries in each
column, followed by the entries for each image, one image per line, as they
is written to disk by the caliban data-transfer daemon.
See the Sample AutoLog output file for an example.
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You can keep watch on the contents of the AutoLog for the current observing day by using an xterm and the Unix tail
command. You will need to resize the xterm and/or shrink the font so that
one line of the AutoLog of interest will fit in the screen. Typical OSIRIS
AutoLog files run 132 characters wide.
Example:
To monitor the AutoLog for observing day 1999 Feb
16/17 on the CTIO 4m, you would type the Unix command
% tail -f /data/Logs/19990216.log
in a properly prepared xterminal window.
You can iconify the window to keep it out of the way, and you should see
each image logged in the AutoLog as the night progresses. Note that the
SunOS system will buffer output to the tail command, so there may be
some lag in when a file appears in the window if you hit the wrong phase of
the buffering.
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% cd ~Logs/
% lpr logfile
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It is possible to use the AutoLog program directly to make a log of one or
more FITS files using a custom format file for the output. Note, however,
that in this mode the AutoLog program is not being run automatically, so it
is used primarily at the end of the night to create a summary of all FITS
files of interest. At present there is no way for observers to control the
output of the AutoLog program as triggered automatically by the data-taking
system.
The AutoLog program is available via the Unix shell as the autolog
executable in the OSU data-taking system software directory as follows:
~osu/bin/autolog
The details of how to run autolog standalone are beyond the scope of
this document. See the AutoLog web page at http://www.astronomy.ohio-state.edu/~pogge/Software/AutoLog/
for details.
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Updated: 2005 June
