The Greenwake project.

Wake vortexes and wind shear are potential causes of accidents and injuries to passengers and crew of all aircraft types. There are currently few options for protection against these phenomena, and the main way of reducing accidents is to impose mandatory separation times between aircraft which can affect the operating performance of airports.

Scan Mechanism

3D Prototype of Scan mechanism

The laser is mechanically scanned over the area of interest.
Two lightweight mirrors
5Hz update rate

Utilising the expertise of Sula Systems gained from 20 years of designing and building mechanical scanning systems for the demanding Space sector.


Detector integration with receiver/ optical bench/ laser

The integration activity combines the experience and cutting-edge technologies provided by
Sula Systems (scanning)
AST (optical bench)
Photonic Science (detector)
SimSoft and UCL (signal processing)

with the expertise of Hovemere Ltd.
Hovemere, has long and successful heritage in Lidar systems, takes responsibility for the receiver and detection optics and the overall integration

Tunnel Trials

VZLU Wind tunnel

Generation of wind effects in tunnel is nearly finalised.Test detection of:

Wake vortices
Wind shear


SESAR Joint Undertaking (Air Traffic Management)

Clean Sky Joint Technology Initiative (Greener Air Transport Products)

WakeNet3-Europe (Wake Vortex and Wake Turbulence)

Seventh Framework Programme Homepage

Le calendrier de la pleine lune et des phases lunaires

Every 29.5 days or so, the moon performs a complete cycle called lunation.
During this cycle of 29 days, 12 hours and 44 minutes, the natural satellite of the Earth goes through eight different phases:

During the first four phases of this cycle, the moon is said to be increasing; during the last four phases, it is decreasing.

Astronomical explanation of this phenomenon
Due to the rotation of the Moon, it is always the same part of its surface that is observable from Earth: the visible face. However, the portion of the visible face lit by the Sun varies.

The Moon is visible only thanks to the light of the Sun which it reflects: during the cycle of the moon, we see its face illuminated from different angles.
The lunar phases observed from Earth are due to the relative positions of the Sun, the Earth and the Moon. The Moon is full when the Sun and the Moon are on either side of the Earth: it appears as a luminous disc.
For a terrestrial observer, when the Moon revolves around the Earth, the visible surface (illuminated by the Sun) decreases (waning moon) until it disappears completely.
It becomes invisible (during the New Moon) when they are both aligned on the same side of the Earth.

How to find your way?
There are various mnemonic means to identify the moon phases when you see the Moon in the sky. The most common is to use letters:
- during the first quarter, the moon has the shape of a D: if we add a leg to this letter, we get the letter P which identifies the First quarter
- conversely, during the last quarter, the moon has the shape of a C: if we add a vertical bar we get the letter d which allows us to recognize the last quarter.

Do not mix up
Be careful not to confuse the concept of waning or waning moon (linked to the phases of the moon) with the concept of ascending or "rising" moon and waning moon.
This second notion describes the change in trajectory of the Moon in the sky.
Indeed, during the lunar cycle, the moon goes up or down compared to the horizon: it is ascending for approximately 13 days and descending for 13 days.

Project Details

Targeted benefits

Improved crew and passenger safety
Increased airport capacity via reduced air traffic separation
Quicker recovery from airport disruption/ delays
Greater environmental hazard awareness

GreenWake objectives

Demonstrate an instrument which can:
Detect WV and WS in a timely manner
Anticipate and mitigate effect of WV and WS on
the aircraft and occupants
Investigate, through simulation, mitigation via flight controls
Develop, demonstrate and validate innovative technologies:
UV LIDAR based
Provide potential air traffic system wide benefits

GreenWake Simulator

Movies of GW Simulator with new scanning pattern:


Evaluate the Lidar performance in realistic flight conditions/li>
Built on existing full scale flight simulation core
The results can be used to
refine the instrument design
evaluate the usability of the data for the purposes of forward flight control
Principle of operation

“Fly” in 3D space and simulate instrument response as turbulence is encountered
Turbulence and atmosphere considered static for the time of encounter (2 ... 3s)
Beam scanning considered dynamic – change of LOS taken into account
A320 used as a platform
Vary encounter scenario and instrument parameters and evaluate the output of the instrument

GreenWake innovations

Modelling and simulation of wake vortex and
wind shear detection by imaging LIDAR system
Development of an imaging Doppler LIDAR
and fast scanning system
Development of detector and data processings
Two detector technologies being assessed
Integration and demonstration of the performance of the system
Creation of 3-d visualisation of the air movement (hazard map)

GreenWake Approach

Establish Requirements
Derive System Concept and optimise
Specify Components
Build sub-systems
Wind tunnel tests
Airfield tests


Green-Wake is a collaborative project funded by the European Commission under the Framework 7 funding scheme, grant number 213254.
The project runs for three years from November 2008 to August 2012.

Part of European activities on wake vortices and aircraft separation
Not procedurally based
Follow-on from Awiator project
Need to identify WV and WS in timely manner


Wake and WakeNet3-Europe on 29 and 30 March 2010
The projects WakeNet3-Europe and Green-Wake will be co-hosting an event on ground-based and on-board wake vortex and wind monitoring sensors at the Thales Research and Technology Centre in Palaiseau, France on 29 and 30 March 2010 which aims to review the use of sensors in wake vortex and wind monitoring in aircraft applications.
Download the agenda here
Global Wake Vortex Conference 9 and 10 November 2009
Eurocontrol are hosting a two-day conference presenting information on some of the wake vortex projects which are presently underway. More information on the event can be found here.
Wakenet3-Europe review of Wake Vortex research
Green-Wake is included in a review of research on Wave Vortices which has been produced by Wakenet3-Europe.
Download the review here
First Green-Wake Project Management Meeting
The first project management meeting took place on 14 and 15 May 2009 at the ADSE headquarters in Amsterdam where the next six months’ work was planned
The first project management meeting took place on 14 and 15 May 2009 at the ADSE headquarters in Amsterdam where the next six months’ work was planned


Schmitt, Nikolaus et al (2007), Forward looking clear air turbulence measurement with the AWIATOR LIDAR sensor,
First CEAS European Air and Space Conference, 2007-09-10 - 2007-09-13, Berlin, Deutschland
Publication 2
Schwarz, Carsten Walter and Hahn, Klaus-Uwe (2007), Automated Pilot Assistance for Wake Vortex Encounters,
First CEAS European Air and Space Conference, 2007-09-10 - 2007-09-13, Berlin, Deutschland
Publication 3
Rahm, S., Smalikho, I., Köpp, F., Characterization of Aircraft Wake Vortices by Airborne Coherent Doppler Lidar,
Journal of Aircraft, Vol. 44, No 3. 2007
Publication 4
GreenWake Poster
Publication 5
The GreenWake Project - Overview (October 2009)
Publication 6
Airfield Trials at Charleroi Airport
Publication 7
Analysis of the possibility for time optimal control of the scanning system.