Abstract: Fourier telescopy (FT), an active high-resolution imaging technique, uses linear interference fringes with different spatial frequencies sweeping across a target. The resulting reflected temporal signal is collected by a large receiver of lower optical quality. Different spatial frequencies of interference fringes, which are essential to extract the target spectrum, are produced by changing position of beams many times in the laboratory. The theory about spectrum extraction is discussed, and a novel beam moving mode is proposed and compared with other two modes respectively used by Trex Enterprises Inc and by Changchun Institute of Optics, Fine Mechanics and Physics from three aspects: the extracted matrix of the target spectrum, the requirements for laboratory instruments and the form of