The circular polarization of vegetation makes up less than 1 percent of the light reflected.
One type of instrument that can detect the signal of polarized light is called a spectropolarimeter, which uses special sensors to separate the polarized fraction.For several years, Patty and his team have been working on a highly sensitive spectropolarimeter for detecting the circular polarization of vegetation.
Called TreePol, it could positively detect circular polarization from several kilometers away.
"The next step we hope to take is to perform similar detections from the International Space Station (ISS), looking down at the Earth," said astrophysicist Brice-Olivier Demory of the University of Bern and MERMOZ.