undef

s1a-iw-grd-vh-20170920t205943-20170920t210008-018464-01f17e-002_filter

s1a-iw-grd-vv-20170920t205943-20170920t210008-018464-01f17e-001_filter

s1a-iw-grd-vv-20170920t205943-20170920t210008-018464-01f17e-001_winddir

s1a-iw-grd-vh-20170920t205943-20170920t210008-018464-01f17e-002_winddir