undef

s1a-iw-grd-vv-20170414t100926-20170414t100951-016139-01aa83-001_filter

s1a-iw-grd-vh-20170414t100926-20170414t100951-016139-01aa83-002_filter

s1a-iw-grd-vh-20170414t100926-20170414t100951-016139-01aa83-002_winddir

s1a-iw-grd-vv-20170414t100926-20170414t100951-016139-01aa83-001_winddir