undef
s1a-iw-grd-vv-20170215t161335-20170215t161404-015296-019126-001_filter
s1a-iw-grd-vh-20170215t161335-20170215t161404-015296-019126-002_filter
s1a-iw-grd-vv-20170215t161335-20170215t161404-015296-019126-001_winddir
s1a-iw-grd-vh-20170215t161335-20170215t161404-015296-019126-002_winddir