undef

s1a-iw-grd-vv-20180212t060706-20180212t060731-020569-023330-001_filter

s1a-iw-grd-vh-20180212t060706-20180212t060731-020569-023330-002_filter

s1a-iw-grd-vh-20180212t060706-20180212t060731-020569-023330-002_winddir

s1a-iw-grd-vv-20180212t060706-20180212t060731-020569-023330-001_winddir