Single peak atomic frequency discriminator for 589 nm Doppler lidar

Area of Science:

• Atmospheric physics
• Optical engineering
• Remote sensing

Background:

• Doppler lidar systems are crucial for atmospheric wind field detection.
• Existing systems face challenges in daytime operation and full-altitude coverage.
• The 589 nm wavelength is significant for mesopause region wind measurements.

Purpose of the Study:

• To develop and validate a single-peak atomic frequency discriminator (SPAFD) for 589 nm Doppler lidar.
• To enhance the capability of Doppler lidar for daytime wind profiling across various atmospheric layers.
• To demonstrate the performance of the integrated SPAFD system for continuous wind observations.

Main Methods:

• Development of a SPAFD integrating narrowband filtering and high-precision frequency discrimination at 589 nm.
• Theoretical simulations and experimental verification of the SPAFD's detection sensitivity.
• Integration of the SPAFD into a 589 nm three-frequency Doppler lidar system.
• Validation through continuous 5-hour daytime wind observations.

Main Results:

• The SPAFD achieved a peak transmittance of 70% and a FWHM of 2 GHz.
• The integrated lidar system successfully performed daytime wind field detection in the mesopause region.
• Daytime wind profiling was enabled from the troposphere to the stratosphere.
• Continuous 5-hour observations demonstrated 1-hour temporal and 1 km spatial resolution.
• Wind speed uncertainty of ±5 m/s was achieved at 40 km altitude during daytime.

Conclusions:

• The developed SPAFD significantly improves Doppler lidar capabilities for daytime atmospheric wind measurements.
• The system enables wind profiling across a wide altitude range, from the troposphere to the mesopause.
• Future enhancements in laser technology will allow for full-altitude atmospheric wind measurements using this SPAFD system.