undef
s1a-ew-grd-vv-20180303t020023-20180303t020127-020844-023bfa-001_filter
s1a-ew-grd-vh-20180303t020023-20180303t020127-020844-023bfa-002_filter
s1a-ew-grd-vv-20180303t020023-20180303t020127-020844-023bfa-001_winddir
s1a-ew-grd-vh-20180303t020023-20180303t020127-020844-023bfa-002_winddir