Modified Soil Adjusted Crop Residue Index (MSACRI): A new index for mapping crop residue

The authors present a new index for mapping and estimating the crop residue cover fraction: the MSACRI (Modified Soil Adjusted Crop Residue Index). This index exploits the mid infrared channels: 1.55 /spl mu/m to 1.75 /spl mu/m and 2.10 /spl mu/m to 2.35 /spl mu/m. Compared to the visible, these channels are characterized by large transparence in relation to atmospheric constituents. In extreme atmospheric conditions, the MSACRI is subject to a slight reduction of approximately 4%. It offers better discrimination of soils/residue and shows quite good dynamics in the presence of residue with average values close to /spl plusmn/0.03 for bare soil and close to 0.70 for full cover residue.