undef

s1a-iw-grd-vv-20170829t002620-20170829t002645-018131-01e74d-001_filter

s1a-iw-grd-vh-20170829t002620-20170829t002645-018131-01e74d-002_filter

s1a-iw-grd-vv-20170829t002620-20170829t002645-018131-01e74d-001_winddir

s1a-iw-grd-vh-20170829t002620-20170829t002645-018131-01e74d-002_winddir