undef

s1a-iw-grd-vh-20160716t175832-20160716t175857-012177-012e20-002_filter

s1a-iw-grd-vv-20160716t175832-20160716t175857-012177-012e20-001_filter

s1a-iw-grd-vh-20160716t175832-20160716t175857-012177-012e20-002_winddir

s1a-iw-grd-vv-20160716t175832-20160716t175857-012177-012e20-001_winddir