ARCHITECTURES AND SYNCHRONIZATION TECHNIQUES FOR COHERENT DISTRIBUTED REMOTE SENSING SYSTEMS

Phase, frequency and time synchronization is a crucial
requirement for many applications as such as multi-static
remote sensing and distributed beamforming for
communications. The literature on the field is very wide, and
in some cases, the requirements of the proposed
synchronization solution may surpass the ones set by the
application itself. Moreover, the synchronization solution
becomes even more challenging when the nodes are flying or
hovering on aerial or space platforms. In this work, we
compare and classify the synchronization technologies
available in the literature according to a common proposed
framework, and we discuss the considerations of an
implementation for distributed remote sensing applications.
The general framework considered is based on a distributed
collection of autonomous nodes that try to synchronize their
clocks with a common reference. Moreover, they can be
classified in non-overlapping, adjacent and overlapping
frequency band scenarios