undef

s1b-iw-grd-hv-20160920t175919-20160920t175944-002156-0039d9-002_filter

s1b-iw-grd-hh-20160920t175919-20160920t175944-002156-0039d9-001_filter

s1b-iw-grd-hh-20160920t175919-20160920t175944-002156-0039d9-001_winddir

s1b-iw-grd-hv-20160920t175919-20160920t175944-002156-0039d9-002_winddir