  Multi-platform radar networks (MPRNs) are an emerging sensing technology due
to their ability to provide improved surveillance capabilities over plain
monostatic and bistatic systems. The design of advanced detection,
localization, and tracking algorithms for efficient fusion of information
obtained through multiple receivers has attracted much attention. However,
considerable challenges remain. This article provides an overview on recent
unconstrained and constrained localization techniques as well as multitarget
tracking (MTT) algorithms tailored to MPRNs. In particular, two data-processing
methods are illustrated and explored in detail, one aimed at accomplishing
localization tasks the other tracking functions. As to the former, assuming a
MPRN with one transmitter and multiple receivers, the angular and range
constrained estimator (ARCE) algorithm capitalizes on the knowledge of the
transmitter antenna beamwidth. As to the latter, the scalable sum-product
algorithm (SPA) based MTT technique is presented. Additionally, a solution to
combine ARCE and SPA-based MTT is investigated in order to boost the accuracy
of the overall surveillance system. Simulated experiments show the benefit of
the combined algorithm in comparison with the conventional baseline SPA-based
MTT and the stand-alone ARCE localization, in a 3D sensing scenario.
