Micro-pulse upconversion Doppler lidar for wind and visibility detection in the atmospheric boundary layer

TL;DR

This paper introduces a novel, compact, and safe Doppler lidar system utilizing upconversion detection for accurate wind and visibility measurements in the atmospheric boundary layer, demonstrating high stability and agreement with standard sensors.

Contribution

It presents the first development of a versatile, all-fiber, eyesafe Doppler lidar using upconversion detection with integrated-optic components and robust performance over extended periods.

Findings

System achieves less than 0.1% error over 9 weeks

Successfully detects atmospheric wind and visibility over 48 hours

Shows good agreement with ultrasonic wind sensors

Abstract

For the first time, a versatile, eyesafe, compact and direct detection Doppler lidar is developed using upconversion single-photon detection method. An all-fiber and polarization maintaining architecture is realized to guarantee the high optical coupling efficiency and the system stability. Using integrated-optic components, the conservation of etendue of the optical receiver is achieved by manufacturing a fiber-coupled periodically poled Lithium niobate waveguide and an all-fiber Fabry-Perot interferometer (FPI). The so-called double-edge direct detection is implemented using a single-channel FPI and a single upconversion detector, incorporating time-division multiplexing method. The relative error of the system is lower than 0.1% over 9 weeks. To show the robust of the system, atmospheric wind and visibility over 48 hours are detected in the boundary layer. In the intercomparison experiments, lidar shows good agreement with the ultrasonic wind sensor (Vaisala windcap WMT52), with standard deviation of 1.04 m/s in speed and 12.3{\deg} in direction.