Abstract: The instantaneous ranging passive location problem based on the spherical wave model,which utilizes an LBI structured system,is discussed.By using geometry theories and phase difference without ambiguities,the emitter’s range and AOA can be detected in a single pulse.Ambiguity elimination for phase difference measurement data is mainly discussed under the spherical wave model.Then a possible resolving method is put forward with the principle for ambiguity elimination.Corresponding demands on measurement methods and equipment are also given,and it is proved to be correct by the MATLAB simulation.