I am working with chandrayaan M3 hyper spectral data. I need to create a band depth image for identifying mineral abundances. How do i calculate the continuum reflectance value for producing a band depth image? Is that a constant value for the whole band or should i calculate the continuum reflectance for each pixel of the band. The formula given for calculating band depth is BD = 1- Reflectance at a specific wavelength/Continuum reflectance at that wavelength.