undef

s1a-iw-grd-vv-20170831t001004-20170831t001029-018160-01e82d-001_filter

s1a-iw-grd-vh-20170831t001004-20170831t001029-018160-01e82d-002_filter

s1a-iw-grd-vv-20170831t001004-20170831t001029-018160-01e82d-001_winddir

s1a-iw-grd-vh-20170831t001004-20170831t001029-018160-01e82d-002_winddir