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La Silla Science Operations: NTT

How to Use the Zero Point Quick Tool

Version 1.0 2003-12-15 M. Billeres

The script has to be runned after each night of observation with SOFI. It passes through all the images taken during the night, recognises the ones made with the templates SOFI_cal_img_StandardStar and measures for each set of data the zero point. It's from now the semi-automatic way to check the zero point. The goal is to create a "database" of measurements of the zero points, all over the year.
So it has to be runned as often as possible to have as many measurements as we can.

To run the script :

1). Open a MIDAS session in the wg5off machine :
                > inmidas

2). Go to the directory where the data are.
                midas> cd /data/raw/YYYY-MM-DD

3) Run the script sofi_zpoint.prg:
                midas> @@ sofi_zpoint

The script picks automatically the dome flats corresponding to the instrument mode/filter combinasion.

The script creates different files :
- in the same directory:
** zpoint_YYYY-MM-DD.dat file where you have all the  value for the zero points for  all the stars found in the directory. an example here.
** zpoint_YYYY-MM-DD.tbl : a midas table with the relevant information : name of the star, instrument mode, filter, instrumental magnitude, zero point and rms of the zero point. an example here.

** a serie of *.paf files, with all the outgoing information of isaacp, for all the stars. an example here.
- All these files are copied in the directory /data/NTTOPS/pipeline_database/SOFI/Photometry/ in a sub-directory YYYY-MM-DD/ created
automatically. These is our local archive.

The midas tables can be used to look the evolution of the zero points, and to plot the magnitude vs the airmass to evaluate the extinction correction.
Be careful: eliminate the bad points.

If the message " NO STANDARD STARS TO USE" appears at the end, it's because there's no standard stars done with the standard template.

If the script crashes, send me (mbillere@eso.org) an email with the error message (if there's one) and don't worry.

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