Coherent lidar airborne windshear sensor: performance evaluation

Area of Science:

• Aviation safety
• Atmospheric remote sensing
• Laser technology

Background:

• Windshear poses a significant threat to aircraft safety, highlighted by the 1985 Dallas/Fort Worth International Airport crash.
• The NASA/FAA National Integrated Windshear Program aims to develop effective windshear detection systems.
• Existing detection methods require improvement for timely pilot warnings.

Purpose of the Study:

• To define a measurable windshear hazard index detectable from an aircraft.
• To evaluate the performance of coherent laser radar (lidar) systems for windshear detection.
• To provide pilots with crucial information about future wind conditions along their flight path.

Main Methods:

• Conducted a technology analysis and end-to-end performance simulation of competing lidar systems.
• Measured signal-to-noise ratios and wind velocity errors for different lidar technologies.
• Focused on Ho:YAG lidar at 2.1 micrometers and CO(2) lidar at 10.6 micrometers.

Main Results:

• Both Ho:YAG and CO(2) lidar systems can detect the line-of-sight component of windshear threats.
• Detection range extends 2-4 km ahead of the aircraft, providing 20-40 seconds of warning time.
• Effective detection is achievable even in moderately heavy precipitation.

Conclusions:

• Coherent lidar technology offers a viable solution for airborne windshear detection.
• The developed windshear hazard index can be remotely sensed, enhancing pilot situational awareness.
• A Coherent Lidar Airborne Shear Sensor (CLASS) is under development for flight evaluation, promising improved aviation safety.