Four-band radiometer for portable and mobile measurements of canopy reflectance and red edge position

Spectral measurements are closely related to the amount of green canopy material. Especially the ratio vegetation index, RVI, calculated as the ratio of near-infrared and red reflectance has been used extensively in agricultural research because of its close correlation with e.g. canopy area index and chlorophyll content. A portable four-band radiometer was designed and developed in 2001 in order to compare the predicting power and sensitivity to varying illumination conditions etc. of RVI, other vegetation indexes and red edge position (REIP) (Broge et al., 2002). Available mobile systems will be upgraded with the new IDA electronics.