Optical vegetation coverage is a better parameter for estimating vegetation biomass

Optical vegetation coverage can be defined as the ratio of the optical information content of the actual vegetation to that of at the full of vegetation in pixel. Its reflectance model of NOAA/AVHRR is as follows: COV=RA2-RA1-rso/RA2V-RA1V-rso Where: Cov is optical vegetation coverage; R-A2 and R-A1 are respectively the reflectances of the second and the first channel; R-A2V and R-A1V are respectively the reflectance of the second and the first channel at the full of vegetation;r(so) is a constant, which is the difference of soil reflectance between the second channel and the first channel. Similarily,its radiance model of NOAA/AVHRR is as follows: COV=BA2-BA1-bso/BA2V-BA1V-bso Its geometric meaning is analogous to the ratio of the projection of plant branches and leaves to pixel area. OVC has removed effects of soil background, and shows the weight of vegetation optical information, moreover,it has a uniform standard, as a parameter for estimating vegetation biomass, it is better than DVI, RVI and NVI. This parameter is used to monitor vegetation growing in Xinjiang and achieved good results. In order to extract the spectral information of soil water contents, C-ov is used to decompose pixels and removed the vegetation effects