undef

s1a-ew-grd-hv-20170606t153516-20170606t153625-016915-01c254-002_filter

s1a-ew-grd-hh-20170606t153516-20170606t153625-016915-01c254-001_filter

s1a-ew-grd-hv-20170606t153516-20170606t153625-016915-01c254-002_winddir

s1a-ew-grd-hh-20170606t153516-20170606t153625-016915-01c254-001_winddir