Idea: validate/correct the positions of sources in a data table

(e.g.s. from tabular sky services, local data)

Algorithm:

1. import a database;
2. determine field center: from data (median database RA/DEC); from user (xy catalog relative to a central position);
3. cross-match to trusted (e.g., 2MASS) skynode: xmatch (large sigma);
4. client side minimize the residuals of the matches: use a fit function (WCS polynomial); transformation matrix;
5. apply fit function to entire input catalog: add revised positional columns to input table;
6. rematch corrected catalog to skynode: using xmatch (small sigma);
7. exploration of the quality of fit: view residual fit map; view smoothed residual map;
8. add residual fit columns to database;
9. add matched trusted database identifier(s) to input catalog: 2MASS designation

-- AugustMuench - 09 Sep 2006