undef
s1a-iw-grd-vh-20170908t220242-20170908t220307-018290-01ec26-002_filter
s1a-iw-grd-vv-20170908t220242-20170908t220307-018290-01ec26-001_filter
s1a-iw-grd-vv-20170908t220242-20170908t220307-018290-01ec26-001_winddir
s1a-iw-grd-vh-20170908t220242-20170908t220307-018290-01ec26-002_winddir