undef

s1a-ew-grd-hv-20170927t154231-20170927t154336-018563-01f498-002_filter

s1a-ew-grd-hh-20170927t154231-20170927t154336-018563-01f498-001_filter

s1a-ew-grd-hv-20170927t154231-20170927t154336-018563-01f498-002_winddir

s1a-ew-grd-hh-20170927t154231-20170927t154336-018563-01f498-001_winddir