undef

s1a-iw-grd-vv-20170424t205136-20170424t205202-016291-01af33-001_filter

s1a-iw-grd-vh-20170424t205136-20170424t205202-016291-01af33-002_filter

s1a-iw-grd-vv-20170424t205136-20170424t205202-016291-01af33-001_winddir

s1a-iw-grd-vh-20170424t205136-20170424t205202-016291-01af33-002_winddir