This paper reports the development, the complete characterization, and the first outdoor field trial of a coherent dual-band photonics-based radar implemented through integrated photonic circuits. The dual band radar transceiver has been implemented on a silicon-on-insulator platform, and is capable of operating up to the Ku-band. It has been packaged and engineered on a printed circuit board for its use in a complete radar system. The electronic RF front-end in S- and X-bands and the digital baseband equipment have been developed in order to guarantee performance aligned with the state of the art of conventional radars. The developed apparatus has been characterized in S- and X-band in terms of sensitivity, linearity, phase noise, and conversion efficiency, both at chip and system level. The impact and issues related to the used fabrication platform and to the packaged approach have been analyzed. The outdoor field trial has been carried out in a relevant maritime environment close to the port of Livorno (Italy). First, X-band radar acquisitions of a complex maritime scene using a rotating antenna has allowed to verify the radar behavior by comparing the detected scene with official data provided by the automatic identification system mounted on the observed ships. A false alarm probability of 2×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−5</sup> has been demonstrated, aligned with radar state of the art. Then, S- and X-band range/velocity acquisitions allowed to confirm the coherent dual band operation, posing the basis for the next step: the development of adapted coherent data fusion algorithms for target imaging.