Water vapour mixing ratio and ozone measurements by a solar blind Raman lidar

Summary form only given. Daytime monitoring of water vapour is of peculiar interest because many significant meteorological phenomena occur more often during the day than at night. Then, Raman lidar systems based either on KrF excimer (248.4 nm) or quadrupled Nd:YAG (266 nm) lasers have been developed. The mixing ratio of water vapour is determined by the ratio between Raman shifted H/sub 2/O and N/sub 2/ signals multiplied by the differential transmissivity q(z) between the two shifted wavelengths. We show, by a propagation error calculation, that under reasonable assumptions the systematic error is lower than the statistical error obtained when the Raman DIAL method is utilised, at least at the higher altitudes. This alternative determination of q(z) makes it possible to extend the range of measurement.