undef

s1a-ew-grd-hh-20150919t172606-20150919t172707-007787-00ad59-001_filter

s1a-ew-grd-hv-20150919t172606-20150919t172707-007787-00ad59-002_filter

s1a-ew-grd-hv-20150919t172606-20150919t172707-007787-00ad59-002_winddir

s1a-ew-grd-hh-20150919t172606-20150919t172707-007787-00ad59-001_winddir