undef

s1a-iw-grd-hv-20160801t061410-20160801t061440-012403-013596-002_filter

s1a-iw-grd-hh-20160801t061410-20160801t061440-012403-013596-001_filter

s1a-iw-grd-hh-20160801t061410-20160801t061440-012403-013596-001_winddir

s1a-iw-grd-hv-20160801t061410-20160801t061440-012403-013596-002_winddir