undef

s1a-iw-grd-vv-20170818t222720-20170818t222745-017984-01e2e2-001_filter

s1a-iw-grd-vh-20170818t222720-20170818t222745-017984-01e2e2-002_filter

s1a-iw-grd-vh-20170818t222720-20170818t222745-017984-01e2e2-002_winddir

s1a-iw-grd-vv-20170818t222720-20170818t222745-017984-01e2e2-001_winddir