A pure rotational Raman lidar using double-grating monochromator for temperature profile detection

A pure rotational Raman lidar is constructed for measurements of vertical temperature profiles of atmosphere. A fiber-coupled, double-grating monochromator is used as the filter system so that a high spectral resolution of <0.23 nm and an out-of-band rejection rate of 10⁷ are achieved. Comparison with in-situ measurements indicates that the accuracy of atmospheric temperature measurements using this lidar system is better than 1.1 K up to an altitude of 10 km. Different effects on signal accuracy resulting from various noise sources are analyzed and uncertainties in temperature due to detection noises are estimated.