Enhancing Global Aviation Safety with Micro Pulse LiDAR

Sigma Space Staff

Volcanic ash is a recurring impediment to normal air-traffic operations in Europe, Asia and South America due to potential jet engine damage caused by the razor-sharp particles in dense ash plumes.

A notable example is the 2010 eruption of the Eyjafjallajökull volcano in Iceland that shut-down air traffic throughout Western Europe for seven days, with intermittent closings necessary as new ash plumes continued to enter the European airspace. More than 300 airports were closed, 100,000 flights were cancelled, and 10 million passengers were impacted. This economic disaster prompted research organizations to place more emphasis on developing effective volcanic ash monitoring systems.

Evaluation of aerosols detection networks for aviation

To address the need for better information about volcanic ash events, the Toulouse Volcanic Ash Advisory Centre (VAAC) asked Météo-France (MF), the French national meteorological service, to focus on the ash issue. MF set out to determine the best method of providing accurate information about the size and concentration of volcanic particles from the ground up to a minimum of 12 kilometres altitude.

The subsequent research efforts included the following activities:

• Tracking plumes of volcanic ash or dust through the atmosphere

• Understanding local air quality

• Providing warnings to air traffic controllers, meteorologists, and industrial sites related to aerosol events

During the summer of 2012, using desert dust as a proxy, MF collected data provided by several LiDAR sensors and ceilometers and in-situ measurements using balloon-borne particle counters and aircraft sensors to assess their effectiveness in tracking aerosols.

Using various sensors and the associated location of the instruments, numerical weather predictions (NWP) were used to forecast different synoptic weather, considering the following factors:

• Vicinity of main air routes

• Coverage of the Atlantic coast for ash coming from Iceland and the Mediterranean Sea emitted by the Italian volcanoes

• Impact on MOCAGE (Modéle de Chimie Atmosphérique de Grande Echelle), the French model for chemical species transport

Results of Network Study Point to MiniMPL

After MF’s initial evaluation, several network designs were studied to determine which one provides the best cost/ benefit ratio. Based on criteria of cost and robustness, MF bought six Sigma Space MiniMPL LiDAR sensors.

“We decided to place five of the MiniMPL in fixed locations at Lille, Trappes, Brest, Momuy and Aleria,” said JeanLuc Lampin, Studies and Development Engineer MétéoFrance. “The sixth MiniMPL is being kept as a mobile lidar. In case of an ash event, the Volcanic Ash Advisory Centre will decide the best place to deploy in terms of the atmospheric circulation and the location of the plume to obtain the best coverage.”

In the future, additional MPL’s will be added to the inventory to expand coverage and develop a comprehensive nation-wide network.

MiniMPL provides new atmospheric details critical to aviation safety

MF’s 3,100 employees are focused on developing the infrastructure and leading-edge technologies necessary to collect meteorological observations for a better understanding of the current atmospheric state. Atmospheric studies are critical for safe airport operations.

To improve global and regional weather modelling and forecasting, MF operates a hybrid network of aerosol LiDAR sensors with a re-deployable mobile component for volcanic ash early warning and detection.

The MiniMPL’s ability to automatically measure depolarization makes characterizing aerosol types feasible for researchers.

“The MiniMPL network is performing very well for MétéoFrance,” said Yunhui Zheng, director of optical engineering at Sigma Space. “By continuously monitoring the atmosphere with a network of depolarization LiDAR sensors, possible air-traffic interruptions due to volcanic ash or major dust events can be prevented or mitigated.”

The MiniMPL uses a laser with a range up to 15 km, as well as dual polarization. The dual polarization backscatter measurements allow for very high accuracy — better than 0.7 per cent. This data enables authorities to discriminate between the occurrence of pure water clouds and the presence of volcanic ash plumes, ash/water cloud mixtures, and ash concentration profiles. All measurement data is analysed and reported in seconds.

Elevating Atmospheric Monitoring

Micro Pulse LiDAR (MPL) instruments, designed by Sigma Space, help scientists, meteorologists and air quality professionals monitor aerosols to better understand the structure of our atmosphere. 

MPL’s long-range capabilities and high-quality signal increase efficiency and accuracy of the data capture process for improved atmospheric monitoring. Originally designed for NASA, MPL uses eye-safe lasers, precision photon counting, and built-in data analysis to deliver the best signal-to-noise ratio and thus the most reliable information in this category.

Sigma Space is part of Hexagon (Nasdaq Stockholm: HEXA B; hexagon. com), a leading global provider of information technologies that drive quality and productivity improvements across geospatial and industrial enterprise applications.

For more information, visit: www.micropulseLiDAR.com