undef

s1a-iw-grd-vv-20160915t101654-20160915t101719-013062-014b52-001_filter

s1a-iw-grd-vh-20160915t101654-20160915t101719-013062-014b52-002_filter

s1a-iw-grd-vv-20160915t101654-20160915t101719-013062-014b52-001_winddir

s1a-iw-grd-vh-20160915t101654-20160915t101719-013062-014b52-002_winddir