I'm working on a project using hyperspectral data collected in a greenhouse. The data is in radiance (mW/m^2*2str*nm) and I'm trying to convert this to reflectance. We did take images of the calibration board before collecting the data. This white and dark calibration board is in the first image but none of the subsequent images. What would be the simplest way to convert the data to reflectance? (I don't have the license for FLAASH.)