A method of calibrating a spectral imaging system is disclosed. The spectral imaging system comprises an interferometer having a beam splitter and at least a first reflector and a second reflector. The method comprises: obtaining data pertaining to an interference pattern model, operating the spectral imaging system to provide an interference pattern of a received light beam, and varying a relative orientation between at least two of: the beam splitter, the first reflector and the second reflector, until the interference pattern of the input light beam substantially matches the interference pattern model.