Analysis of vegetation isolines in Red-NIR reflectance space

The characteristic behavior of red-near-infrared (NIR) reflectance-based ve getation isolines were analyzed by focusing on its three features: the slop e, NIR-intercept, and the intersection between the vegetation isoline and t he soil line. These properties are the key factors in understanding variati ons of vegetation index values with changes of canopy background brightness , known as background noise. The analysis was conducted based on a vegetati on isoline equation derived by using the representation of canopy reflectan ce by the adding method. The isoline parameters, slopes, and NIR-intercepts of vegetation isolines were numerically obtained by the SAIL canopy model. Some of the known behaviors of the vegetation isoline were simulated and a nalyzed in detail. (C) Elsevier Science Inc., 2000.