A hyperspectral imaging system and method are presented for use in reconstruction of spectral data of an object. The system comprises: a pixel matrix of a detector; a tunable dispersive unit in front of the pixel matrix; and a control system. The control system comprises: a controller for tuning the dispersive unit during n image acquisition sessions to provide n different partially overlapping spectral transmission profiles of the dispersive unit; and a control unit which is in data communication with the detector and is configured and operable for processing n image data pieces generated by the pixel matrix in said n image acquisition sessions respectively, each being indicative of a spectral image detected by the pixel matrix and corresponding to the different spectral transmission profile of the dispersive unit, and determining the reconstructed spectral data of the object.