undef

s1a-iw-grd-vv-20160424t101648-20160424t101717-010962-010741-001_filter

s1a-iw-grd-vh-20160424t101648-20160424t101717-010962-010741-002_filter

s1a-iw-grd-vv-20160424t101648-20160424t101717-010962-010741-001_winddir

s1a-iw-grd-vh-20160424t101648-20160424t101717-010962-010741-002_winddir