Diode-laser-based direct-detection Doppler wind lidar: design and initial results

Area of Science:

• Atmospheric Science
• Optical Remote Sensing
• Meteorology

Background:

• Accurate wind velocity profiles are crucial for weather forecasting and atmospheric research.
• Existing instruments face challenges in measuring winds across both the planetary boundary layer and the free troposphere due to aerosol dependency or systematic errors.
• Direct-detection Doppler wind lidar (DWL) systems often struggle with unknown aerosol optical properties, impacting accuracy.

Purpose of the Study:

• To present initial results from a novel diode-laser-based direct-detection Doppler wind lidar (DWL).
• To evaluate the system's capability in measuring clear-air wind velocity profiles in both the planetary boundary layer and the free troposphere.
• To demonstrate a DWL system overcoming limitations of existing technologies.

Main Methods:

• Development of a diode-laser-based direct-detection Doppler wind lidar (DWL) operating at 780 nm.
• Utilizing the double-edge technique combined with ancillary backscatter ratio measurements.
• Employing a frequency-stabilized diode laser in a master oscillator power amplifier configuration.

Main Results:

• Horizontal testing against an anemometer yielded a mean bias of 0.17 m/s and a standard deviation of 1.5 m/s.
• Vertical testing achieved wind velocity retrieval with <3 m/s random uncertainties from 500 m to 10.5 km (night) and 4.5 km (day).
• A time-varying systematic bias of approximately 2 m/s was observed over 17 days.

Conclusions:

• The prototype DWL demonstrates feasibility for measuring wind in both the planetary boundary layer and the free troposphere.
• The system shows potential for improved clear-air wind profiling in atmospheric research.
• Further refinement may address observed systematic biases for enhanced operational use.