Every entry in an index of the catalogue can have a link to the data that it describes.
There is a resource location (URL), also called enclosure, that can be associated in the entry metadata.
This URL can be extracted easily using opensearch-client. For instance:
opensearch-client "https://catalog.terradue.com/sentinel1/search" enclosure
The resource locations returned by the catalogue point to a data gateway like:
https://store.terradue.com/download/sentinel1/files/v1/S1A_IW_SLC__1SDH_20160915T090555_20160915T090624_013061_014B4B_4793
then the download will be performed via the Data Gateway that enables many function such as caching to allow the best download performance of the data requested.
Now you can use the download url with a simple curl command
curl -v -L -o <your_download_path> <enclosure_url>
i.e.
curl -v -L -o /tmp/S1A_IW_SLC__1SDH_20160915T090555_20160915T090624_013061_014B4B_4793.zip https://store.terradue.com/download/sentinel1/files/v1/S1A_IW_SLC__1SDH_20160915T090555_20160915T090624_013061_014B4B_4793
or using one of the ciop-copy tool installed in your sandbox:
ciop-copy -s -U -O <your_download_path> <enclosure_url>
i.e.
ciop-copy -s -U -O /tmp/ https://store.terradue.com/download/sentinel1/files/v1/S1A_IW_SLC__1SDH_20160915T090555_20160915T090624_013061_014B4B_4793
you can even pipe the query and download request
opensearch-client "https://catalog.terradue.com/sentinel1/search" enclosure | ciop-copy -s -U -O /tmp/
more information on download in the Data API documentation.