undef

s1a-iw-grd-vv-20150911t100121-20150911t100146-007666-00aa37-001_filter

s1a-iw-grd-vh-20150911t100121-20150911t100146-007666-00aa37-002_filter

s1a-iw-grd-vh-20150911t100121-20150911t100146-007666-00aa37-002_winddir

s1a-iw-grd-vv-20150911t100121-20150911t100146-007666-00aa37-001_winddir