undef

s1a-ew-grd-vv-20170304t144459-20170304t144559-015543-0198b5-001_filter

s1a-ew-grd-vh-20170304t144459-20170304t144559-015543-0198b5-002_filter

s1a-ew-grd-vv-20170304t144459-20170304t144559-015543-0198b5-001_winddir

s1a-ew-grd-vh-20170304t144459-20170304t144559-015543-0198b5-002_winddir