Multiple scattering effects on the localization of two point scatterers

Multiple scattering effects are commonly ignored in the detection and estimation of scatterers in signal processing research, because the energy of the first-order scattering is much larger than that of higher-order components. Although multiple scattering can significantly increase the estimation precision of point scatterers, it does not always lead to an improvement. Identifying conditions under which multiple scattering is beneficial or detrimental to estimation in a general setup is still an open problem. In this paper, we consider the effects of multiple scattering on the localization of two point scatterers. By comparing the Fisher information matrix on location parameters when multiple scattering exists and does not exist, we show analytically that information on ranges can benefit estimating directions of arrival via multiple scattering when the two scatterers are in far-field and well resolved.