Phase 3 FTP Upload

Phase 3 FTP server: SSL/TLS encryption requirement dropped.

As of 12 June 2012 any standard FTP client can be used to transfer Phase 3 data including the clients previously suggested like lftp and FileZilla. The requirement to use the SSL/TLS encryption layer for connections to the Phase 3 FTP server at ESO has been dropped. now accepts plain FTP connections (port 21) whereas the support for FTP over TLS has been removed.

Having defined the data release, you are ready to transmit your data products to ESO for which a dedicated FTP server has been installed. You may use any FTP client of your choice. You may consider the powerful and free FileZilla ( as FTP client, which provides a graphical user interface and supports abort/resume functionality among other useful features, or the command-line client lftp (, which comes with many Linux distributions by default.

First, connect to the FTP server at

and login with your ESO User Portal credentials.

Then, change to the directory

/<Phase 3 programme>/<Data collection name>/batch_<Data release number>

For example, for the VISTA Hemisphere Survey with

Programme Name: VHS

Data Collection Name: SGP

Data Release: #1

the complete path would read


Thereafter, you can start transferring your set of products. Since FITS checksums are employed to safeguard the data transfer against transmission errors, it is essential that you properly update the respective checksum keywords beforehand. For non-FITS format ancillary files there is a special mechanism in place to catch possible transmission errors employing their MD5 hashes. You have the option to specify the MD5 hash using the dedicated keyword ASSOMi in the science file defining the data set. Then, the Phase 3 validator detects any data inconsistency before the files will be archived.

 The directory and the data deposited therein are visible and accessible just for you as the programme owner and for your delegates. In the course of preparing the data release you can modify files on the FTP server as needed, including file removal.

As a data provider you also control the data flow in time. You may transfer the files for a data release in one go or you may accumulate them on the FTP server over a period of time before you close the release. This flexibility allows adapting the submission process to the particular needs due to data processing and verification activities of each programme.

If no more data is being added, the data will be kept on the FTP server for a period of three months unless the release is closed before.