undef

s1a-ew-grd-vv-20160904t223257-20160904t223357-012909-01467a-001_filter

s1a-ew-grd-vh-20160904t223257-20160904t223357-012909-01467a-002_filter

s1a-ew-grd-vh-20160904t223257-20160904t223357-012909-01467a-002_winddir

s1a-ew-grd-vv-20160904t223257-20160904t223357-012909-01467a-001_winddir