Development of an Onboard Doppler Lidar for Flight Safety

Abstract

Air turbulence has become a major cause of significant injuries and aircraft damages. Timely advanced warning of turbulence ahead of an aircraft may allow pilots to take appropriate action to minimize potential damage, such as reducing speed and securing passengers and unsecured objects, or to avoid the turbulence altogether. The aim of our research is to develop a practical, onboard, Lidar-based proactive sensor that will detect air turbulence in clear air at a range of 5 n miles (9.3 km) at cruising altitudes. In February 2007 we successfully measured wind speeds approximately 3 n miles (5.6 km) ahead of an aircraft in low-altitude flight experiments, and in a subsequent experiment in July of the same year, we succeeded in detecting air turbulence before encountering it. An upgraded 5-n-mile Lidar for low altitudes was developed in fiscal year 2007, and has successfully measured wind speeds at ranges up to 5 n miles in ground tests. This paper describes the master development plan of our Lidar turbulence sensor and the results of basic flight and ground experiments.

Aviation Turbulence

“…In 1999, the Japanese JAXA initiated a similar program for the development of an airborne coherent Doppler lidar. Prototypes of this fiber-based lidar system have been flown on JAXA's Beechcraft (for low altitudes research) in 2007 (Inokuchi et al 2009) and its Gulfstream II aircraft in 2010 (Inokuchi et al 2010;Inokuchi et al 2014). All these flight tests of different coherent lidar systems show the high potential of this technology.…”

Performance validation on an all-fiber 1.54-μm pulsed coherent Doppler lidar for wind-profile measurement

“…19 Mitsubishi Electric Corporation developed an airborne 1.5-μm pulsed CDL, which was capable of detecting as far as 9.3 km with modifiable range resolutions, and the wind velocity measurement accuracy of the prototype was inspected in comparison with L-band wind profiler. [20][21][22] In 2011, Leosphere displayed a long-range lidar (Windcube 200S), which could measure three-dimensional (3-D) *Address all correspondence to Xiaopeng Zhu, E-mail: xp_zhu@siom.ac.cn; Xiaolei Zhu, E-mail: xlzhu@siom.ac.cn wind profiles up to 7 km in distance with 70-m range resolution, and the radial velocity with 0.5-m∕s velocity resolution was validated by another lidar (Windcube 70). 23 In 2016, Zhai et al 24 developed a 1.5-μm pulsed CDL with variable spatial resolution from 15 to 60 m; its discrepancies with radiosonde observation results were within acceptable limits.…”

Disturbance suppression via robust MPC using prior disturbance data application to flight controller design for Gust Alleviation

“…In the 1970s, the turbulence is measured at the head of the aircraft; however, the lead time before encountering the turbulence becomes very short as the aircraft speed increases, thus the measured turbulence data cannot be effectively used. On this issue, as electronic and optic technologies have advanced these years, turbulence can be measured several seconds ahead [5], [6]. Considering these backgrounds, design methods for disturbance suppression controllers exploiting a priori measured disturbance data have been desired.…”