Errors

[Thomas Droege <tdroege2@earthlink.net>]

You all seem to be jumping to conclusions about some of the tass data being
off by one day.  It is possible to check this and I have offered a scheme. 
It might require looking at the image, but possibly Michael can tell from
the data he has.  

We have built a lot of checks into the tass data.  It is possible to
investigate most things.  Let us do that before jumping to conclusions. 
Could someone send me the specific days that are proposed to be "one day
off"?  I can then look at the logs and at the images and see if there is
something amiss.  I don't have things stored by GSC numbers.  

BTW anyone who thinks that data is error free is in the wrong business. 
The tass data is taken every possible night.  The definition of possible is
written into the code.  It is not limited to perfect nights or there would
be no data.  Data is not processed for "bad" nights.  The information is
available in the data sets to set the cut higher if that is helpful for
your purpose.  We have set the cut were we have because we think that is a
good spot.  But it depends.  Michael Sallman has looked at the information
in the data and marked the data points that are at the lower end of the
distribution.  That is useful, but the cut is his opinion.  There is a
continuum of possible cuts.  The information is available if you want to
use it. 

Nothing can eliminate "operator" error but more care.  I do the best I can.
Procedures are getting better over time.  We did call the first year of
data the "Engineering" run to indicate that we were still working out the
bugs.  Perhaps those of you that can't cope with such things should not use
the tass data.  To answer a question, there are currently over 200 million
measurements.   

I would like to reply in detail to JG who seems to be having a grumpy day. 
But I need to attend a Fermilab conference on the DECam project for the
next couple of days.  I promise to get back to it.  

Tom Droege


Tom  Droege Jennifer Malpass
tdroege2@earthlink.net