Envisat WSS & WSM

[priit111]

Additional modes to be supported.

[priit111]

GDAL does not support WSS mode, but GDAL webpage for Envisat reader claims all lvl1 ASAR product are supported.

WSS is a special file format added later than the original formats.

This is an argument for removing GDAL from other products as well, however would require bigger refactoring.

[johntruckenbrodt]

Just for the protocol.. WSM is now supported.

[priit111]

I will add the details of the status:

WSM is properly merged and provides reasonable output, however an issue the quality and an implementation details of sarsen and Envisat file format is discussed in detail here(#58). This might be an non-issue, however it needs further investigation that could not be completed during the ARD4ASAR project.

WSS basic support is present in here. However multiple issues persist:

1. The deburst is not implemented correctly, the final output looks noisy with invalid data lines. Needs further study and improvements.
2. Due to lack of GDAL support, the internal file parsing is completely different. This needs further consideration and possibly hints at complete removal of using GDAL.
3. The subswaths - SS1, SS2, SS3, SS4, SS5 should either be merged automatically or possibly work with just one subswath. At the moment the wss_support works with a new user paremeters as this is easier.

Nevertheless, the commit stated above would be the basis for potential finalization of the WSS support.