undef
s1a-iw-grd-vh-20160818t104902-20160818t104936-012654-013de1-002_filter
s1a-iw-grd-vv-20160818t104902-20160818t104936-012654-013de1-001_filter
s1a-iw-grd-vh-20160818t104902-20160818t104936-012654-013de1-002_winddir
s1a-iw-grd-vv-20160818t104902-20160818t104936-012654-013de1-001_winddir