undef
s1a-iw-grd-vh-20180807t203522-20180807t203547-023145-02839f-002_filter
s1a-iw-grd-vv-20180807t203522-20180807t203547-023145-02839f-001_filter
s1a-iw-grd-vv-20180807t203522-20180807t203547-023145-02839f-001_winddir
s1a-iw-grd-vh-20180807t203522-20180807t203547-023145-02839f-002_winddir