undef

s1b-iw-grd-vh-20170809t085739-20170809t085807-006861-00c13c-002_filter

s1b-iw-grd-vv-20170809t085739-20170809t085807-006861-00c13c-001_filter

s1b-iw-grd-vh-20170809t085739-20170809t085807-006861-00c13c-002_winddir

s1b-iw-grd-vv-20170809t085739-20170809t085807-006861-00c13c-001_winddir