CTRANS/ROMAFOT

CTRANS/ROMAFOT int_tab [base_1] [base_2] [pol_deg]

This command uses the two tables generated by CBASE/ROMAFOT and derives the analytical transformation to pass from coordinates on ``frame 1'' to coordinates on ``frame 2''. If the transformation is considered satisfactory by the operator (e. g. if the rms is of the order of a few tenths of a pixel or better), the command changes the coordinates on the intermediate table in order to use these as inputs in the next program frame. In practice, after having completed reductions on the first frame, one should copy the intermediate table and transform it. If the transformation produces a rms larger than a few tenths of a pixel, this means that a mismatching exists on the objects selected with CBASE/ROMAFOT. In some cases a high rms could indicate the necessity of an higher polyminal order (``N''), for the analytical transformation, provided that more than

$${N^{2}+3N+2 \over 2}$$

objects are available for the base.

At this point it could be useful to check the transformation with the command
ANALYSE/ROMAFOT. In this case the new frame and the intermediate table just transformed must be used and the keys D1, D2... Dk will allow the display of objects with the old parameters (height, $\beta$ and so on) on the new image.

With the key L, in addition, it is possible to determine the approximate central intensity of the star and the associate sky luminosity. These values are useful to adjust the parameters in input with the command