undef

s1a-ew-grd-vv-20170207t015458-20170207t015558-015171-018d33-001_filter

s1a-ew-grd-vh-20170207t015458-20170207t015558-015171-018d33-002_filter

s1a-ew-grd-vv-20170207t015458-20170207t015558-015171-018d33-001_winddir

s1a-ew-grd-vh-20170207t015458-20170207t015558-015171-018d33-002_winddir