undef

s1a-iw-grd-vv-20171111t100031-20171111t100100-019216-020899-001_filter

s1a-iw-grd-vh-20171111t100031-20171111t100100-019216-020899-002_filter

s1a-iw-grd-vv-20171111t100031-20171111t100100-019216-020899-001_winddir

s1a-iw-grd-vh-20171111t100031-20171111t100100-019216-020899-002_winddir