undef

s1a-iw-grd-vh-20170207t063005-20170207t063030-015174-018d4a-002_filter

s1a-iw-grd-vv-20170207t063005-20170207t063030-015174-018d4a-001_filter

s1a-iw-grd-vv-20170207t063005-20170207t063030-015174-018d4a-001_winddir

s1a-iw-grd-vh-20170207t063005-20170207t063030-015174-018d4a-002_winddir