Photonics-Based Radar-Lidar Integrated System for Multi-Sensor Fusion Applications

A photonics-based radar-lidar integrated system is proposed, which consists of a photonics-based radar and a frequency-modulated continuous-wave (FMCW) lidar. Since the photonic generation of RF signals is used, the transmitter can simultaneously generate linear frequency-modulated (LFM) radio-frequency (RF) and optical signals. Meanwhile, similar data acquisition methods are shared by the radar and lidar subsystems because FMCW ranging method is used in both of them. In the integrated system, the lidar subsystem provides high-resolution 3D images and velocity distributions, while the radar subsystem can implement real-time imaging with high frame rates. An experiment is carried out, in which a system consisting of a K-band radar and a 1550-nm FMCW lidar is used. The bandwidth of the radar and lidar subsystems are 8-GHz and 4-GHz. The standard deviations of displacements between the measured and the expected distances are 0.342 cm and 0.997 cm for the radar and lidar subsystems, respectively. For multi-sensor fusion applications, the 3D image and velocity distribution of a static cardboard and a spinning disk are obtained by the lidar subsystem, while the inverse synthetic aperture (ISAR) imaging for the spinning disk is achieved by the radar subsystem. Since some parts of the system are shared by the lidar and radar subsystems, the integrated system has a compact configuration, which is a potential configuration of the on-chip radar-lidar fusion system. Moreover, the performance of the lidar and radar subsystems are higher than the commonly used radar-lidar fusion system, which can be further enhanced by sophisticated data fusion algorithms.