undef

s1a-iw-grd-vh-20160402t100020-20160402t100044-010641-00fd8b-002_filter

s1a-iw-grd-vv-20160402t100020-20160402t100044-010641-00fd8b-001_filter

s1a-iw-grd-vv-20160402t100020-20160402t100044-010641-00fd8b-001_winddir

s1a-iw-grd-vh-20160402t100020-20160402t100044-010641-00fd8b-002_winddir