undef

s1b-iw-grd-hv-20160817t174257-20160817t174316-001660-00250f-002_filter

s1b-iw-grd-hh-20160817t174257-20160817t174316-001660-00250f-001_filter

s1b-iw-grd-hh-20160817t174257-20160817t174316-001660-00250f-001_winddir

s1b-iw-grd-hv-20160817t174257-20160817t174316-001660-00250f-002_winddir