undef

s1a-iw-grd-vh-20170411t215225-20170411t215259-016102-01a96f-002_filter

s1a-iw-grd-vv-20170411t215225-20170411t215259-016102-01a96f-001_filter

s1a-iw-grd-vh-20170411t215225-20170411t215259-016102-01a96f-002_winddir

s1a-iw-grd-vv-20170411t215225-20170411t215259-016102-01a96f-001_winddir