Downloading and using the SOPHIE FITS files
The archived data products of the SOPHIE spectrograph can be downloaded in the FITS format. This is the usual format used for astronomical data.Content of the FITS files
Different data-products can be downloaded in FITS. They are:
Depending on the observation template, the fiber B data may also be included in file. This is the case when fiber = 'SKY', or fiber = 'WAVE'. When fiber='SKY', the ccf of the B fiber is always computed using a G2 mask (beside the telluric emission, the sky spectrum contains diffracted Solar light).
A SOPHIE FITS file may therefore contain the following extensions:
Suppose you are interested in all the reconnected (s1d) spectra of HD028307 and want to download the FITS files to your disk. You can naturally go to the web interface with your favorite browser and download each spectrum one by one. But this can become tiresome.
An alternative is to run a script from your machine to download all the files, and we recommand the widely used wget program, probably available on your machine if it is running Linux.If it is not available, you may easily and freely install it, as it is a GNU open source utility.
The web interface of the archive offers the possiblity to obtain the list of wget
commands that would download all the files for a selection of observations.
To obtain this list, simply click on the proper link at the bottom of the result page.
To download a single s1d file, the command looks like:
You can download the list of wget command, or copy and paste it into a file, and you can execute it doing for example sh <file> (if you are using the sh shell)...Advanced usages
To encapsulate the the access to the archive in a script or in an application program, you need to understand some of the parameters of the URL. Those which may be the most interesting to play with are:
Downloading a FITS file (c=i), consists in (i) injecting the data in a pipeline, (ii) processing this file along the pipeline and (iii) streaming the FITS flow to the htpp answer. The injection command has the form: o=sophie:[s1d,1045721], where the first argument in the square brackets is the 'dataproduct' (s1d, e2ds or ccf), and the second is 'seq', the unique sequence number of the SOPHIE spectra. For ccf there is a third parameter which is the name of the cross-correlation mask, for example: o=sophie:[ccf,1045801,K5].
The FITS processing pipeline is described by the z= parameter. You can find the various commands and the syntax by observing the URL created when you edit a pipeline using the 'customize' link.
Last updated on : 28.02.2014