A method for generating index raster files associated with an area of interest (AOI) uses a computer coupled to a remote sensing device via a network, wherein the computer includes an input device, a display, and a memory. The method includes receiving only three image raster files relating to the AOI from the remote sensing device, and receiving at least one set of three spectral control points (SCP) via the input device. The method also includes generating at least two independent vegetation index (VI) raster files and a soil brightness index (SBI) raster file based on the image raster files and the at least one set of three SCPs, storing each of the SBI raster file and the at least two VI raster files into the memory, and selectively displaying at least one of the SBI raster file and the at least two VI raster files.