A relative positioning system is described. At least one emitter is attached to a first object, where each of the at least one emitters includes: an electromagnetic radiation source configured to generate electromagnetic radiation over a band of wavelengths, and a prism arranged to refract and disperse the electromagnetic radiation from the electromagnetic radiation source according to the wavelength of the electromagnetic radiation. At least one electromagnetic radiation detector is attached to a second object arranged to detect the wavelengths of some of the electromagnetic radiation refracted and dispersed by a respective prism. At least one processor is configured to determine the relative position of the first object and the second object based on the detected wavelengths by the at least one electromagnetic radiation detector.