earth online



H2O-DIAL system aboard meteorological research aircraft, Falcon 20E
The H2O-DIAL system aboard DLR's
meteorological research aircraft, Falcon 20E.

What was the purpose of WALEX 2005?

Design and performance studies for satellite missions measuring water vapour (e.g. WALES or SPACE-WAVES) require information on the real 2D structure of water vapour and aerosol/clouds in the troposphere, which can only be provided with sufficiently high spatial resolution and coverage by airborne water vapour lidar measurements. In this context the objective of WALEX 2005 is to extend the acquisition of representative lidar measurements of water vapour and aerosol/cloud properties to sub-Tropical and Tropical regions in the Indian Ocean and Micronesia, regions characterised by monsoon and intense inner tropical circulation.

What was the outcome of WALEX 2005?

Following the result obtained in the frame of this study, the following recommendations can be drawn. First, the study proves once again that high quality aerosol and humidity lidar observations can be gained from long-range ferry flights. Such airborne data, especially if gathered in data-sparse regions such as southeast Asia, are of high relevance for predicting and optimising the performance of future spaceborne lidar instruments.

Next opportunities will be during transfer and local measurements flights to field campaigns, especially in the frame of THORPEX, a global research programme dedicated to reduce the risk of high-impact weather to the society, the economy and the environment under the auspices of the WMO. One of the key issues of THORPEX is to test new observing strategies for remote sensing instruments to obtain data in data-sparse regions.

Download the WALEX 2005 Final Report

Campaign summary
Data Coverage (Years)2002, 2005
Geographic SiteIndian Ocean and Micronesia and North and Middle Atlantic
Field of applicationAtmosphere
Data size2.6
LIDAR dataAvailable

Digital Object Identifier: - WALEX: "Technical Support for the Acquisition of Water Vapour DIAL and Aerosol Measurements: Water Vapour Lidar Experiment WALEX 2005 "


The campaign data is available online via FTP upon submission of a data access request. An active EO Sign In account is required to submit the request.

For further information about the EO Sign In Service you can visit TellUs

Should you need support please contact EOHelp



Subscribe to our newsletter to receive highlights of recent news from Earth Online

Cookies & Privacy

We use cookies which are essential for you to access our website and to provide you with our services and allow us to measure and improve the performance of our website. Please consult our Cookie Notice for further information or to change your preferences.