SDR Implementation of a Testbed for Synchronization of Coherent Distributed Remote Sensing Systems

• Published in: IGARSS 2020 - 2020 IEEE International Geoscience and Remote Sensing Symposium pp. 6588 - 6591
• Main Authors: Merlano-Duncan, J. C., Querol, J., Martinez-Marrero, L., Krivochiza, J., Camps, A., Chatzinotas, S., Ottersten, B.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 26.09.2020
• Subjects: distributed beamforming; Doppler effect; multi-static remote sensing systems; Receivers; Remote sensing; Satellite broadcasting; SDR implementation; Synchronization; Synthetic aperture radar; Transceivers
• ISSN: 2153-7003
• DOI: 10.1109/IGARSS39084.2020.9324220

Remote Sensing from distributed platforms has become attractive for the community in the last years. Phase, frequency, and time synchronization are a crucial requirement for many such applications as multi-static remote sensing and also for distributed beamforming for communications. The literature on the field is extensive, and in some cases, the requirements an complexity 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 discuss the synchronization considerations for the implementation of distributed remote sensing applications. The general framework considered is based on a distributed collection of autonomous nodes that synchronize their clocks with a common reference using inter-satellite links. For this purpose, we implement a synchronization link between two nodes operating in a full-duplex fashion. The experimental testbed uses commercially available SDR platforms to emulate two satellites, two targets, and the communication channel. The proposal is evaluated considering phase and frequency errors for different system parameters.