Proposal to include polarization_mode and antenna_receive_configuration

[bps2023]

The following proposals are motivated by the German TerraSAR-X mission.

The current SAR extension already includes the detailed polarization channel information in sar:polarizations. What we are missing from TerraSAR-X mission point of view is the polarization_mode with valids single, dual or quad.

Another - probably very TerraSAR-X specific - parameter is the antenna receive configuration. TerraSAR-X quad pol and along-track interferometry acquisitions are only available in an experimental way when operatng the primary and redundant receiver chain in parallel. Since the along-track interferometry acquisitions are taken in instrument mode Stripmap and polarisation mode single, we need the antenna_receive_configuration with valid DRA for dual-receive to distingush them from the standard Stripmap single pol data taken taken in antenna_receive_configuration SRA for single-receive.

Currently, we have to include the antenna_receive_configuration and the polarization_mode in a custom TerraSAR-X extension. It would be nicer to have all the necessary acquisition input in one extension, namely the SAR one.

Birgit Schättler (former TerraSAR-X / TanDEM-X Ground Segment Systems Engineer)

[m-mohr]

Hi @bps2023

Please excuse my naivity, I'm not a SAR expert at all.

Can't you derive the polarization_mode from sar:polarizations? You list VV, VH => dual, you list VV only => single, etc. That's probably not super easy to use in search though (needs some kind of "count" aggregation in the search expression) so if that's a usecase, it might indeed make sense to add the property specifically.

With regards to the configuration, is that meant to be an object with various key value pairs?
I suspect that the variety in what would be included in this field is rather broad, so that means there would be no standardization possible and it also can't easily be searched if it's an object. Keeping such specific information in a separate extension makes sense to me. I think. I assume the eopf:instrument_configuration_id falls into a similar category and is also in a separate extension as it is not applicable to other SAR constellations.