undef

s1a-iw-grd-vv-20160904t163143-20160904t163208-012905-014658-001_filter

s1a-iw-grd-vh-20160904t163143-20160904t163208-012905-014658-002_filter

s1a-iw-grd-vv-20160904t163143-20160904t163208-012905-014658-001_winddir

s1a-iw-grd-vh-20160904t163143-20160904t163208-012905-014658-002_winddir