undef

s1a-iw-grd-vh-20171009t102528-20171009t102553-018735-01f9cc-002_filter

s1a-iw-grd-vv-20171009t102528-20171009t102553-018735-01f9cc-001_filter

s1a-iw-grd-vh-20171009t102528-20171009t102553-018735-01f9cc-002_winddir

s1a-iw-grd-vv-20171009t102528-20171009t102553-018735-01f9cc-001_winddir