  Phase, frequency, and time synchronization are crucial requirements for many
applications, such as multi-static remote sensing and communication systems.
Moreover, the synchronization solution becomes even more challenging when the
nodes are orbiting or flying on airborne or spaceborne platforms. This paper
compares the available technologies used for the synchronization and
coordination of nodes in distributed remote sensing applications. Additionally,
this paper proposes a general system model and identifies preliminary
guidelines and critical elements for implementing the synchronization
mechanisms exploiting the inter-satellite communication link. The distributed
phase synchronization loop introduced in this work deals with the
self-interference in a full-duplex point to point scenario by transmitting two
carriers at each node. All carriers appear with different frequency offsets
around a central frequency, called the application central-frequency or the
beamforming frequency. This work includes a detailed analysis of the proposed
algorithm and the required simulations to verify its performance for different
phase noise, AWGN, and Doppler shift scenarios.
