undef

s1a-ew-grd-hv-20160604t171827-20160604t171851-011564-011a8c-002_filter

s1a-ew-grd-hh-20160604t171827-20160604t171851-011564-011a8c-001_filter

s1a-ew-grd-hv-20160604t171827-20160604t171851-011564-011a8c-002_winddir

s1a-ew-grd-hh-20160604t171827-20160604t171851-011564-011a8c-001_winddir