الفهرس | Only 14 pages are availabe for public view |
Abstract This dissertation addresses the problem of detecting multiple wide band sources and estimating their angles of arrival and the frequency spectrum based on the signal received by a sensor array in the presence of noise. The sources are considered as wide-band incoherent/coherent signals. Most of super-resolution Direction Of Arrivals (DOA’s) estimation techniques in modem radio reconnaissance systems are based on eigen decomposition off-line analysis of received signals covariance matrix. The common requirement to these techniques is that the array of sensors should be linear and uniform. In many applications, the geometry of the array may be subject to deformation in the field, or the elements are randomly distributed. In these cases, an approach for processing the signal of arbitrary array geometry is necessary. This approach must be general to include the cases of elliptical arrays on the hull of ships, V-and Y shaped arrays of radio reconnaissance systems, and others. For alleviating the problem, which arises with the arbitrary arrays, a pre processing technique to the received signal has been recently applied in a form convenient only for planar structure. This dissertation introduces the pre-processing technique to the signal of arbitrary array in a form that can be applied to non-planar structure. The developed computer code applies Multiple Signal Classification (MUSIC) estimator m conjunction with the spatial smoothing technique. The simulation results discuss the performance of the MUSIC estimator in the two cases of uniform and arbitrary arrays. It also discusses the application of the pre-processing technique to V-& Y Shaped arrays. Direction finding of radio activities using an arbitrary array conformed to a spherical surface is described. It is based on a transformation of the signal of the arbitrary array into a uniform linear virtual one. In this form, a selected direction finding estimator can be applied in the environment ’ . . ’ of Incoherent/Coherent sources. The sources are considered to be essentially narrow band. |