undef

s1a-ew-grd-hv-20170312t155138-20170312t155238-015661-019c3a-002_filter

s1a-ew-grd-hh-20170312t155138-20170312t155238-015661-019c3a-001_filter

s1a-ew-grd-hh-20170312t155138-20170312t155238-015661-019c3a-001_winddir

s1a-ew-grd-hv-20170312t155138-20170312t155238-015661-019c3a-002_winddir