Re: Tass-Landolt Comparison

["Thomas Droege" <tdroege2@earthlink.net>]

A while back I did this for Brian Skiff's big photometry file.  I recall
60,000 or so stars.  This includes lots of Landolt stars.  The result was
quite nice.  There was the expected error at the higher mags.  I have put a
correction in a program and plan to run this all again for the paper.  The
mean error was very small showing that we do a good average job.  The sigma
was higher than I would like.  Sigh.  But still in the expected range.  

Some day I will get back to computing now that I have run out of cameras to
fix.  

The current project is to understand the memory boards.  There is something
funny.  As I write Dan is building a test fixture so I can try to
understand the problem.  Slowly I am getting all the problems beat down. 
If I live long enough, there will be good data. 

Tom 


> [Original Message]
> From: Michael Sallman <msallman@pro-ns.net>
> To: Tass <tass@listserv.wwa.com>
> Date: 2/26/2004 5:55:55 PM
> Subject: Re: Tass-Landolt Comparison
>
> If I had looked a little further in the email, I would have noticed
> Michael R.'s mention of Tech note 97.
> http://www.tass-survey.org/tass/technotes/tn0097.html
> In which he has information and plots of, wait for it....
> Landolt - TASS comparisons.
> Good thing mine look to be nearly identical to his.
> And we now have a few more stars.
>
> As they say, "Great Michaels think alike"
> :-)
>
> Mike
>
> Michael Sallman wrote:
> > I was cleaning out some of my old mail the other day, and I ran across a
> > thread from last November, where Tom and Michael R. had looked at MarkIV
> > data for 4 or 5 Landolt stars.
> > I decided to see what I could find in the database, now that Tom has
> > pretty much completed a full sweep of the northern sky.
> > I downloaded the Landolt list from
> > http://www.tass-survey.org/tass/catalogs/catalogs.html#landolt
> > and matched it to stars in the database. I came up
> > with 806 matches.
> >  From this list, I took a look at those that had at least 10 good
> > measurements in the database, and had V-R and R-I measurements in the
> > Landolt list. This reduced the number to 306 stars.
> > I have made some plots of the data (Landolt V vs. TASS V, etc.)
> > and put them on my website:
> > http://sallman.tass-survey.org/servlet/markiv/template/Landolt.vm
> > The g(x) lines are simple linear approximations of the data.
> > 
> > It looks like the TASS I values are almost always fainter than the 
> > Landolt I.
> > 
> > If anyone would like the data, just let me know.
> > 
> > Mike
> > 
> > P.S. I have finished loading the November and December data into the
> > database.
> > 
> > 
> > 
> > 
> > 
> > 
> > 
>
>
>