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Soliciting criticism
> Hey folks,
>
> I'm hoping some of you have the desire to critique, and offer suggestion
> about the graphs here: http://robertcreager.mystarband.net/ . The are all
> from Tom's data, night 2157 (from a few weeks ago). As the graph titles
> imply, one is reduced from source extractor, and one from sps2x.
>
> Speaking of source extractor, does anyone have a set of values which might
> be appropriate for reducing Mark IV images? I grabbed Glenn Gombert setup
> from 1996, but at this point, I'm shooting in the dark as to how to
> improve the reduction. If anyone wants to direct, I'll be happy to make
> changes and keep re-running the reduction. It takes about 4 hours from
> start to finish for reducing night 2157, so I can get two runs per day at
> home.
> The basic steps are:
> * Create master dark and flats from median data
> * Adjust the object data by: mean * (object[i][i] - dark[i][j] ) /
> flat[i][j] where mean is the mean of a central box of the flat field
> * Do the reduction (sps2x, source extractor) in V-I pairs
> * Match the reduction data to transform into ra/dec
> * Try to match both to subset of Tycho2 data
> * If both match, use in next step
> * If only one matches, match other band to the matching one to
> calculate ra/dec
> * Collate the V-I pairs from previous
> * Solve for magnitude adjustment from collated data
> * Use stars which match the Tycho2 subset
> * Fit a line to the raw color (V-I) vs. magnitude delta (Tycho2 -
> measured) for each V and I
> * Iterate over the line fit, removing 4 sigma data, until either no
> more data was removed, we've removed too much data (10% removed) or the
> RMS error is below 0.05
> * Import star list into database, and match stars within 0.004
> degrees.
> * Produce graphs included from the previous data
> The majority of the stars in the graph have 30+ measurements.