Observations - Download Data#

Assuming you have already performed a query (e.g., using query_surveys(), query_instrument(), or query_main()) and have a resulting table of data products, you can download the actual datasets using the retrieve_data() method. This method takes as input a list of data product IDs (dp_id) obtained from the query results.

>>> from astroquery.eso import Eso
>>> eso = Eso()

>>> data_files = eso.retrieve_data(table['dp_id'][:2])
INFO: Downloading datasets ... [astroquery.eso.core]
INFO: Downloading 2 files ... [astroquery.eso.core]
INFO: Downloading file 1/2 https://dataportal.eso.org/dataPortal/file/MIDI.2007-02-07T07:01:51.000 to /Users/foobar/.astropy/cache/astroquery/Eso [astroquery.eso.core]
INFO: Successfully downloaded dataset MIDI.2007-02-07T07:01:51.000 to /Users/foobar/.astropy/cache/astroquery/Eso/MIDI.2007-02-07T07:01:51.000.fits.Z [astroquery.eso.core]
INFO: Downloading file 2/2 https://dataportal.eso.org/dataPortal/file/MIDI.2007-02-07T07:02:49.000 to /Users/foobar/.astropy/cache/astroquery/Eso [astroquery.eso.core]
INFO: Successfully downloaded dataset MIDI.2007-02-07T07:02:49.000 to /Users/foobar/.astropy/cache/astroquery/Eso/MIDI.2007-02-07T07:02:49.000.fits.Z [astroquery.eso.core]
INFO: Uncompressing file /Users/foobar/.astropy/cache/astroquery/Eso/MIDI.2007-02-07T07:01:51.000.fits.Z [astroquery.eso.core]
INFO: Uncompressing file /Users/foobar/.astropy/cache/astroquery/Eso/MIDI.2007-02-07T07:02:49.000.fits.Z [astroquery.eso.core]
INFO: Done! [astroquery.eso.core]

>>> data_files
['/Users/foobar/.astropy/cache/astroquery/Eso/MIDI.2007-02-07T07:01:51.000.fits',
 '/Users/foobar/.astropy/cache/astroquery/Eso/MIDI.2007-02-07T07:02:49.000.fits']

The file names returned in data_files point to the decompressed datasets (without the .Z extension) that have been locally downloaded. The default location of the decompressed datasets can be adjusted by providing a destination keyword in the call to retrieve_data().

>>> data_files = eso.retrieve_data(table['dp_id'][:2], destination="./eso_data/")

By default, if a requested dataset is already found, it is not downloaded again from the archive. To force the retrieval of data that are present in the destination directory, use continuation=True in the call to retrieve_data().

When downloading datasets, you can optionally retrieve associated calibration files by using the with_calib argument. This makes use of the ESO CalSelector service (see the CalSelector information page).

Available options:

  • None (default): Download only the requested science data.

  • "raw": Include raw calibration files associated with each dataset.

  • "processed": Include processed calibration files (i.e., reduced/calibrated).

>>> # Download science data with raw calibrations
>>> data_files = eso.retrieve_data(table['dp_id'][:2], with_calib="raw")

>>> # Download science data with processed calibrations
>>> data_files = eso.retrieve_data(table['dp_id'][:2], with_calib="processed")