undef
s1a-iw-grd-vv-20180717t205946-20180717t210011-022839-027a00-001_filter
s1a-iw-grd-vh-20180717t205946-20180717t210011-022839-027a00-002_filter
s1a-iw-grd-vh-20180717t205946-20180717t210011-022839-027a00-002_winddir
s1a-iw-grd-vv-20180717t205946-20180717t210011-022839-027a00-001_winddir