3.1. int_hart

Function: Hartmann test for a list of couples of images Syntax: int_hart H_file P_file dispaxis outfile1 outfile2

Parameters:

• H_file: The file with the focus, HRimages and HLimages names.
• P_file: File with the coordinates (X,Y) of emission features array.
• dispaxis (= 0): Dispersion axis (0: horizontal axis, 1: vertical axis).
• outfile1: Output with the outfiles names containing the offsets.

• outfile2: Output file with the values of best focus.

Description: This task allow us determine the shifts between the centers along the dispersion axis of several emission features (emission lines array of an arc image) for several images couples. Each couple correspond to an image obtained with the right and the left shutters open and close respectively (HRimage), and the other one with the right and the left shutters close and open respectively (HLimage). These features correspond to isolated arc lines over all field of the detector. A value of the best focus in the positions of these emission lines is obtained too. The H_file is a file which contains in each row the following columns: focus, HRimage and HLimage:

-10000.0	HR1.imh	HL1.imh
-6000.0	HR2.imh	HL2.imh
-2000.0	HR3.imh	HL3.imh
2000.0	HR4.imh	HL4.imh
4000.0	HR5.imh	HL5.imh
6000.0	HR6.imh	HL6.imh
10000.0	HR7.imh	HL7.imh

The P_file is a file of two columns containing the aproximate (with a preciseness of around 1 pixel) coordinates X and Y over the detector of the emission features which correspond to the arc image. An example of P_file:

20	20
520	25
1002	22
23	527
542	532
985	520
24	1003
541	1012
1003	1007

The dispaxis parameter (0: horizontal axis, 1: vertical axis) corresponds to the dispersion axis on the CCD. And the outfile1 is an output file which contains the files names with the values of the shifts between the centres (obtained using the imcntr task) of the emission lines of the HRimage and the HLimage for all emission lines whose approximate coordinates (X,Y) are in P_file.

The outfile2 is the other output file containing the values of the best focus in each point (X,Y) of the P_file file. The outfile2 is typed on display. The best focus in each point is obtained from the offsets (in this point) for the different focus positions. These offsets are fitted to a straight line. The best focus position correspond with the value for which the offset is zero.