undef

s1a-iw-grd-vh-20170811t175018-20170811t175043-017879-01dfb3-002_filter

s1a-iw-grd-vv-20170811t175018-20170811t175043-017879-01dfb3-001_filter

s1a-iw-grd-vv-20170811t175018-20170811t175043-017879-01dfb3-001_winddir

s1a-iw-grd-vh-20170811t175018-20170811t175043-017879-01dfb3-002_winddir