We present a lab prototype of a high spectral resolution UV lidar channel dedicated to calibrate and validate EarthCare lidar. A solution with two Fabry-Pérot etalons combined in line is proposed to achieve high spectral purity in splitting aerosol and molecular backscatter returns. Targeted spectral purity predicted in a model for molecular signal has been achieved with the prototype version. Decoupling etalons by turning wave polarization confirmed to be successful. Compact design implementing pressure tuning solution to adjust etalon effective mirror spacing proved to be efficient. Illuminating etalon from “the back” with He:Ne laser light and monitoring interference fringe diameter demonstrated to be a feasible technique to control etalon alignment.
Serikov et al. (Thu,) studied this question.