Detection of isolated specular reflection for calibration of cloud thermodynamic phase estimation with quantum parametric mode sorting LIDAR

Abstract

Specular reflection can be problematic for the determination of the cloud thermodynamic phase for near-nadir-pointing space LIDARs. A LIDAR system biased towards the specular contribution for backscatter, if near-concurrent to a conventional LIDAR, could calibrate the measurements required for cloud phase determination. One such system which shows promise for this is quantum parametric mode sorting (QPMS) LIDAR. Through a non-linear interaction and time-frequency mode selectivity, this system demonstrates in-band noise-rejection beyond what linear noise filtering can provide. This level of noise-rejection means the signal strength can be minimised, therefore biasing the specular contribution to the return signal. Here we provide a theoretical model of QPMS LIDAR applied to this scenario to instruct its feasibility.