undef

s1a-iw-grd-vv-20170918t095058-20170918t095127-018428-01f075-001_filter

s1a-iw-grd-vh-20170918t095058-20170918t095127-018428-01f075-002_filter

s1a-iw-grd-vv-20170918t095058-20170918t095127-018428-01f075-001_winddir

s1a-iw-grd-vh-20170918t095058-20170918t095127-018428-01f075-002_winddir