Calibration tables are required to provide reference values of wavelength for Th-Ar arc lamp lines, atmospheric extinction or standard star fluxes.
A certain number of tables are distributed
on request in complement to the Midas releases. These tables are
also available on anonymous ftp at the host ftphost.hq.eso.org
(IP number 134.171.40.2). The files to be retrieved are located
in the directory /midaspub/calib and are named README.calib and
calib.tar.Z. Command SHOW/TABLE can be used to visualize the
column name and physical units of the tables. Demonstration
data required to execute the tutorial
procedure TUTORIAL/ECHELLE are also located on this ftp
server in the directory /midaspub/demo as echelle.tar.Z. FTP access
is also provided on the World Wide Web URL:
http://http.hq.eso.org/midas-info/midas.html
The calibration directory contains other information such as characteristic curves for ESO filters and CCD detectors, which can be visualized with the Graphical User Interface XFilter (command CREATE/GUI FILTER).
Figure: Echelle Reduction Scheme