undef

s1a-ew-grd-hh-20160601t115753-20160601t115853-011517-011923-001_filter

s1a-ew-grd-hv-20160601t115753-20160601t115853-011517-011923-002_filter

s1a-ew-grd-hh-20160601t115753-20160601t115853-011517-011923-001_winddir

s1a-ew-grd-hv-20160601t115753-20160601t115853-011517-011923-002_winddir