Feed Forward Clear-Air Turbulence Mitigation: Estimation of Vertical Winds Ahead of an Aircraft

摘要

Coherent Technologies, Inc. (CTI) and AeroTech Research have been investigating the use of onboard lidar measurements and advanced flight control algorithms to mitigate turbulence induced accelerations to commercial aircraft. A key requirement for such a system is to produce accurate estimates of the vertical wind ahead of the aircraft. This work describes the algorithms for wind estimation and their performance, and illustrates how a forward looking wind sensor and advanced flight control algorithms can reduce the effect of turbulence. At cruise altitudes the vertical wind has the largest effect upon an aircraft. However, a radial velocity measurement of the wind directly ahead of an aircraft gives no direct measurement of the vertical wind. A lidar system that desires to measure the vertical wind must overcome this deficiency. The most desirable implementation, in terms of wind measurement accuracy, would be a sensor placed ahead of the aircraft that directly samples the wind field. But for the best effect, the flight control algorithm needs wind field data from hundreds of meters ahead of the aircraft, making this implementation unrealistic.