Solar light gets scattered at cloud top level in Venus ’ atmosphere , in the visible range , which corresponds to the altitude of 67 km .
We present Doppler velocity measurements performed with the high resolution spectrometer MTR of the Solar telescope THEMIS ( Teide Observatory , Canary Island ) on the sodium D2 solar line ( 5890 Ã ) .
Observations lasted only 49 min because of cloudy weather .
However , we could assess the instrumental velocity sensitivity , 31 m s ^ { -1 } per pixel of 1 arcsec , and give a value of the amplitude of zonal wind at equator at 151 \pm 16 m s ^ { -1 } .