WADI’s last flight trials were conducted over 4 months, between April and July 2017, with ONERA’s aerial platform BUSARD instrumented with two hyperspectral cameras and an uncooled infrared camera coupled with ground truth measurements. The aerial platform flew over several areas with a high potential of soil moisture due to artificial water leaks belonging to the water network infrastructure of SCP (Société du Canal de Provence). The result is the development of a rich and unique image database (VNIR, SWIR, TIR) at different weather conditions, types of soil and vegetation and rates of water leaks.
Different data sets from WADI campaigns have been pre-processed (geometrics and radiometric correction, registration) then exploited for the determination of optimised wavelengths for leakage detection. The outcome is a series of maps of different indicators that are believed to reveal the presence of water (water index). In order to provide a water index with the triangle/trapezoid method, it is necessary to combine thermal infrared signal (8-12μm) with OSAVI indice (one wavelength on each side of the red edge, between 0.65μm and 0.675μm and between 0.79μm and 0.87μm). Other indices, obtained by combining two or three reflectance maps in VNIR or SWIR bands, were not selected because of their lower performance (low S/N=signal noise ratio).
In the coming weeks, the most promising cameras will be selected and purchased taking into account all relevant requirements of the application.
Read more about the first part of WADI Busard campaign
4 October 2017
