undef
s1a-iw-grd-vv-20170910t232841-20170910t232906-018320-01ed26-001_filter
s1a-iw-grd-vh-20170910t232841-20170910t232906-018320-01ed26-002_filter
s1a-iw-grd-vv-20170910t232841-20170910t232906-018320-01ed26-001_winddir
s1a-iw-grd-vh-20170910t232841-20170910t232906-018320-01ed26-002_winddir