undef

s1a-iw-grd-vv-20180116t062203-20180116t062228-020176-0226b1-001_filter

s1a-iw-grd-vh-20180116t062203-20180116t062228-020176-0226b1-002_filter

s1a-iw-grd-vh-20180116t062203-20180116t062228-020176-0226b1-002_winddir

s1a-iw-grd-vv-20180116t062203-20180116t062228-020176-0226b1-001_winddir