undef

s1a-ew-grd-hv-20160604t153843-20160604t153943-011563-011a83-002_filter

s1a-ew-grd-hh-20160604t153843-20160604t153943-011563-011a83-001_filter

s1a-ew-grd-hh-20160604t153843-20160604t153943-011563-011a83-001_winddir

s1a-ew-grd-hv-20160604t153843-20160604t153943-011563-011a83-002_winddir