  Radio Tomographic Imaging (RTI) is a phaseless imaging approach that can
provide shape reconstruction and localization of objects using received signal
strength (RSS) measurements. RSS measurements can be straightforwardly obtained
from wireless networks such as Wi-Fi and therefore RTI has been extensively
researched and accepted as a good indoor RF imaging technique. However, RTI is
formulated on empirical models using an assumption of light-of-sight (LOS)
propagation that does not account for intricate scattering effects. There are
two main objectives of this work. The first objective is to reconcile and
compare the empirical RTI model with formal inverse scattering approaches to
better understand why RTI is an effective RF imaging technique. The second
objective is to obtain straightforward enhancements to RTI, based on inverse
scattering, to enhance its performance. The resulting enhancements can provide
reconstructions of the shape and also material properties of the objects that
can aid image classification. We also provide numerical and experimental
results to compare RTI with the enhanced RTI for indoor imaging applications
using low-cost 2.4 GHz Wi-Fi transceivers. These results show that the enhanced
RTI can outperform RTI while having similar computational complexity to RTI.
