undef

s1a-iw-grd-vv-20170731t100948-20170731t101013-017714-01daa9-001_filter

s1a-iw-grd-vh-20170731t100948-20170731t101013-017714-01daa9-002_filter

s1a-iw-grd-vh-20170731t100948-20170731t101013-017714-01daa9-002_winddir

s1a-iw-grd-vv-20170731t100948-20170731t101013-017714-01daa9-001_winddir