undef
s1a-iw-grd-vh-20180824t084311-20180824t084336-023386-028b5c-002_filter
s1a-iw-grd-vv-20180824t084311-20180824t084336-023386-028b5c-001_filter
s1a-iw-grd-vh-20180824t084311-20180824t084336-023386-028b5c-002_winddir
s1a-iw-grd-vv-20180824t084311-20180824t084336-023386-028b5c-001_winddir