undef

s1a-iw-grd-vv-20180502t175025-20180502t175050-021729-0257d0-001_filter

s1a-iw-grd-vh-20180502t175025-20180502t175050-021729-0257d0-002_filter

s1a-iw-grd-vh-20180502t175025-20180502t175050-021729-0257d0-002_winddir

s1a-iw-grd-vv-20180502t175025-20180502t175050-021729-0257d0-001_winddir