undef
s1a-iw-grd-vv-20180823t043758-20180823t043823-023369-028ad1-001_filter
s1a-iw-grd-vh-20180823t043758-20180823t043823-023369-028ad1-002_filter
s1a-iw-grd-vv-20180823t043758-20180823t043823-023369-028ad1-001_winddir
s1a-iw-grd-vh-20180823t043758-20180823t043823-023369-028ad1-002_winddir