undef

s1a-iw-grd-vv-20190912t183503-20190912t183528-028992-0349db-001_filter

s1a-iw-grd-vh-20190912t183503-20190912t183528-028992-0349db-002_filter

s1a-iw-grd-vv-20190912t183503-20190912t183528-028992-0349db-001_winddir