Skip to main content

Archive - FAQ (Getting Data - Data Requests) - Knowledgebase / Archive / FAQ - ESO Operations Helpdesk

Archive - FAQ (Getting Data - Data Requests)

Authors list

ESO Archive Frequently Asked Questions

Getting Data - Data Requests

A complete list of ESO Archive Contents is available here.

Depending on which service you request you may be redirected to the User Portal login page at (for example when requesting proprietary data).

  • How can I download data?
    There are two ways to download the data:
    1. via the Download Portal (new service) at
      where XXXXXXXXXXXXX is a random alphanumeric string which uniquely identifies your Download Portal request.
    2. via the Request Handler (old way) at

The Science Portal leads only to the Download Portal, while all the other query forms still offer both ways of downloading the data.

Be informed that the Request Handler is planned to be decommissioned in Q1 2023.

  • Can I retrieve processed data from the Archive?
    In addition to the raw observations taken at the La Silla Paranal Observatory, the ESO archive also contains various data products:
  • How come some files I requested can be downloaded now whereas before they showed Access =”NO” (Download Portal) or the "Denied Access" icon (Request Handler)?

This is because the access status flag is adjusted dynamically and always shows the current value. At the moment one submits a request, the files may still be under proprietary status. When the same files are revisited by an Archive User after the proprietary period has expired the file's access status will show "Access="YES" (Download Portal) or OK" (Request Handler) allowing for download.

  • How do the download scripts of Download Portal or Request Handler work?

The download scripts or - are both based on a file transfer tool called WGET.

To run them, you need to have WGET installed and working on command line. This package is usually installed by default in Linux, but not in MacOSX or Windows.

The usage of both scripts is as follows:

usage: [-hlp] [-u user] [-X args] [-d args] [-hlp] [-u user] [-X args] [-d args]
         -h            print this help text
         -l            print list of files to download
         -p            prompt for password
         -u username   download as a different user
         -X args       extra arguments to pass to xargs
         -d args       extra arguments to pass to the download program

If the scripts do not work and return an error message mentioning "...use `--no-check-certificate’", please run them as follows:

./ -d "--no-check-certificate"
./ -d "--no-check-certificate"

If you run the download scripts without any option:

  1. You will be asked to enter your password. If you would like to avoid this, you can create a .netrc file in your home directory with the following entry:
     machine login USERLOGIN password USERPASSWORD

    We recommend to ensure that your .netrc file is protected, e.g. by

    chmod go-rxw .netrc
  2. If there is already a .netrc file with an entry related to the dataportal hostname in your home directory, the download will start without prompting for your password. The download will fail if credentials in the .netrc file are wrong.
  3. Note that if the options -p (prompt for password) or -u username (to use another account for download) are specified, you will be prompted for your password, whatever the state of the .netrc file is.


    1. Run the download scripts without any input:

      The scripts will prompt you for a password. The advantage is that the password will not be visible in the command history and there is no need to store it in an environment variable. The main drawback is that some interaction is required between the script and the user who will be prompted for his/her password.

    2. Create a .netrc, then the download scripts can be run as:

      the download will start without prompting for a password and your password will not be visible.

    3. Echo for the password to avoid having it prompted:
      echo -n PASSWORD | ./                             
      echo -n PASSWORD | ./

      the advantage is that again no interaction is required, the drawback is that the password will show up in the history unless it is stored in an environment variable.

  • The download manager of the Request Handler does not seem to work. Can I still retrieve the requested files?

Yes, any file can be downloaded, individually, simply by clicking directly on the file name itself in the listing provided under the Request ID accessed from

You can also download all the files using a shell script provided on the same request page (the page that shows you all the files of your request), located immediately under the title "Requested Datasets", and named downloadRequest<yourrequestID> To make use of that script you should:

  1. Download it to your UNIX desktop (clicking on it)
  2. Move it to the directory where you want to download the files
  3. Change the permissions to make it executable:
    chmod +x downloadRequest<yourrequestID>
  4. Run it:
  • What shall I do when a file download fails?

Try restarting the download for the failed file, the failure might have been caused by a temporary outage of the system or due to a network issue.

If it still does not work, contact us via and we will be glad to assist.

  • What is the maximum number of files I can submit as a request with the Download Portal or the Request Handler?

The maximum number of files that can be requested via the Download Portal is currently 10,000 files per request, and 20,000 files via the Request Handler.

Note however that requesting associated calibrations may dramatically increase the final number of files within a request, and in case of using the Request Handler, it may even hamper the successful completion of the request.

  • How can I check the quality of science observations?

For Service Mode runs, the associated Night Log file is provided together with each science frame when it is requested from the Archive.
If you have a doubt on the quality of a science observation, please first check in the associated Night Log report which contains comments on any issues that could have happened during the observation (e.g. instrument problems), as well as the information about the ambient conditions for that night (seeing, transparency, etc.).

If the information you are looking for is not reported in the NightLog, then please feel free to contact us via

  • Which information can I find in a Night Log?

The Night Log of a given observing night contains any information and comments related to issues occurred during that night. It also reports the ambient conditions measured during the observation.

Below is an example of a Night Log report:

Nightlog information for file UVES.2002-06-16T08:51:25.171
OB grade: C)Out of specs - Repeat
Comment: 2002-07-06: reclassified because of red CCD problems

Red wavelength calibration;
                                     Requested    Fulfilled?
Seeing:                              1.00               Yes
Airmass:                             1.50               Yes
Moon Distance:                       90                 Yes
Sky Transparency:                    2CLR               Yes
Strehl Ratio:                        N/A                N/A

Please find more information about OB grade here.