undef

s1a-iw-grd-vv-20170917t100950-20170917t101015-018414-01f00b-001_filter

s1a-iw-grd-vh-20170917t100950-20170917t101015-018414-01f00b-002_filter

s1a-iw-grd-vv-20170917t100950-20170917t101015-018414-01f00b-001_winddir

s1a-iw-grd-vh-20170917t100950-20170917t101015-018414-01f00b-002_winddir