Effectiveness of simultaneous independent realizations at low carrier-to-noise ratio to improve heterodyne doppler lidar performance. II. Experimental results

A 1.55-μm continuous-wave heterodyne Doppler lidar (HDL) with three receiver–detector units is used to validate experimentally the findings presented in the Guérit et al. companion paper [Appl. Opt. 41, 2232 (2002)] on the effectiveness of independent realizations to improve HDL performance (velocity or power estimates or both) at a low carrier-to-noise ratio (CNR). In fact, noise has a detrimental effect on the accumulation techniques, so in the Guérit et al. companion paper, the chances of getting “;heavy” speckles in HDL signals from many receiver–detector units on a single-or several-shot basis are investigated theoretically and numerically with the Zrnic HDL model. The experimental results enable us to conclude there is a very good agreement (better than 95%) between the performance computed from actual HDL data and from the theoretical predictions.