The problem of resolving the complex interference field at a receiving site, that is caused by multimode propagation at high frequencies, into the individual plane wave components and determining the direction of arrival of these components is considered. The method developed is based on Prony's algorithm. To illustrate the effect of noise on the solution, a first-order linearized model of a statistical study of a two plane wave problem for this conventional Prony's method is presented. A modification of Prony's technique, an eigenvalue approach, allows one to analytically determine the number of waves in the problem, and this approach is less susceptible to the effect of noise. Data obtained from a controlled experiment when a signal from a distant source was repeated and retransmitted at a different location verify that the system as well as the algorithm is capable of resolving waves coming from different directions. Experimental evidence related to multimode as well as single-mode propagation coming from the same source has been obtained.