undef

s1a-iw-grd-vv-20161104t100122-20161104t100147-013791-016281-001_filter

s1a-iw-grd-vh-20161104t100122-20161104t100147-013791-016281-002_filter

s1a-iw-grd-vv-20161104t100122-20161104t100147-013791-016281-001_winddir

s1a-iw-grd-vh-20161104t100122-20161104t100147-013791-016281-002_winddir