undef

s1b-iw-grd-vh-20170918t082719-20170918t082747-007444-00d23f-002_filter

s1b-iw-grd-vv-20170918t082719-20170918t082747-007444-00d23f-001_filter

s1b-iw-grd-vv-20170918t082719-20170918t082747-007444-00d23f-001_winddir

s1b-iw-grd-vh-20170918t082719-20170918t082747-007444-00d23f-002_winddir