undef
s1a-iw-grd-vh-20180815t104130-20180815t104155-023256-02872e-002_filter
s1a-iw-grd-vv-20180815t104130-20180815t104155-023256-02872e-001_filter
s1a-iw-grd-vv-20180815t104130-20180815t104155-023256-02872e-001_winddir
s1a-iw-grd-vh-20180815t104130-20180815t104155-023256-02872e-002_winddir