= Copilot =

`copilot.py` is a script that watches for new images, measures them,
 and produces a plot, `recent.png` to help observers understand what
 the conditions are doing.

Start it from the `mzls@mayall-idl.kpno.noao.edu` account,
{{{
cd ~/obsbot
python copilot.py &
eog recent.png &
}}}

It will monitor the $MOS3_DATA directory, and whenever a new image
comes it, it will measure it, update a little database, and create a
"strip plot" showing the conditions.

The database is in *~/obsbot/obsdb/obsdb.sqlite3*.

An example plot is shown here:

[[Image(recent.png)]]

The top panel shows the seeing.  Any problems with the data we know
how to detect are marked with red vertical bands.  These include:
* readtime -- MAY indicate a duplicated image ("md5sum" is a better
  indicator).
* md5sum -- this image contains identical pixels as a previous image.
  This requires action!  Please see the problem description [[https://desi.lbl.gov/trac/wiki/PublicPages/MayallZbandLegacy/NotesforObservers/Problems#a5.Repeatimages HERE]].
* pixcnt -- the image readout is shifted.  Please have a look at this
  exposure and note in the logs which CCD has the shift.  The shifts
  are pretty easily recognized in the *mscexam* IRAF window -- blocks
  of one of the images will be shifted to the left or right.  Do not
  stop observing.
  This problem is described [[https://desi.lbl.gov/trac/wiki/PublicPages/MayallZbandLegacy/NotesforObservers/Problems#a4.Shiftedimages here]]
* (unlabelled bar) -- it has been a while since the last image has been seen.  Have images stopped being written?  See problem description [[https://desi.lbl.gov/trac/wiki/PublicPages/MayallZbandLegacy/NotesforObservers/Problems#a0.Noimagesbeingwritten here]]  


The second panel shows the Sky brightness.  The "nominal" brightness
is shown by the magenta horizontal line.  In this panel, the pass
number of previous exposures is shown.  (This corresponds to the pass
we thought the image was going to be, not what the actual conditions
delivered.)

The "transparency" panel shows what fraction of the light from stars
is getting through the atmosphere to us.  Around 90% usually indicates
clear photometric conditions.

The "exposure time" panel is complicated.  The hollow black dots show
the actual exposure time of the images we took.  The magenta dots show
the exposure time we should have taken, given the measured conditions
in that image; it's post-facto what we should have done.  We have
lower and upper bounds on the exposure times, 80 and 250 seconds.  If
the "post-facto" target exposure time is below or above the bounds, it
is shown with a triangle, and a circle will also be plotted at the
lower or upper bound line.

The "depth factor" plot just shows our actual exposure time divided by
the post-facto target exposure time.  1 indicates that we're doing
exactly what we should be doing.  Greater than 1 indicates we're
over-exposing, and less than 1 indicates that we're under-exposing.
The vertical labels show the exposure numbers.


Note that zeros and focus frames will not show up on the plot.