Photonics-Based Dual-Band Radar for Landslides Monitoring in Presence of Multiple Scatterers

Abstract

In this paper, a dual-band photonics-based radar system used for precise displacement measures in a multitarget scenario is described. The radar was designed for monitoring applications to prevent both structural failures of buildings and landslides. The radar system exploits the technique of stepped frequency continuous wave signal modulation and the displacement of the targets is evaluated through differential phase measurements. In this work, encouraged by the results already achieved in the single-target scenario, we present an investigation extended to the case of multiple targets. We aim to evaluate the accuracy of the displacement estimation both from a simulated and experimental point of view, and to understand how multiple targets impact on the final estimate of displacements. Simulation results demonstrate that it is possible to achieve a typical accuracy of less than 0.2 mm for distances up to 400 m. These results are confirmed by preliminary experimental outcomes, which take into account different operative conditions with multiple targets. Finally, concluding remarks and perspectives draw the agenda for our future investigations.

Microwave Photonic Radars

“…Therefore, the microwave photonic radar transceiver without optical filters is feasible. The system has been applied for ISAR imaging [383], naval target tracking [384], and landslides monitoring [385], in which two radar signals in the S-and X-bands were handled simultaneously. One key advantage of the dual-band all-optical radar is that the generation and detection of the dual-band radar signals can be achieved by the same transmitter and receiver, which not only makes the system more compact but also ensures the coherence of the signals in the two bands due to the shared MLL, which is highly desired for simplifying the processing in multi-band data fusion.…”

Chip‐Based Microwave‐Photonic Radar for High‐Resolution Imaging

“…[14] Application scenarios of the microwave-photonic radars have also been investigated, such as aircraft/UAV/maritime traffic detection, [7,8,15,16] automotive sensing, [17] and landslides monitoring. [18] Although the existing achievements have demonstrated a significantly improved performance and showed a great potential of the photonic radar, all of the reported microwave-photonic radars are constructed based on discrete optical components, leading to a bulky system with low reliability. Thanks to the longstanding efforts devoted to the photonic integration technologies, chip-based microwave-photonic radar with a dramatic reduction in the footprint is becoming possible.…”

“…[ 14 ] Application scenarios of the microwave‐photonic radars have also been investigated, such as aircraft/UAV/maritime traffic detection, [ 7,8,15,16 ] automotive sensing, [ 17 ] and landslides monitoring. [ 18 ]…”

X-Band Photonic-Based Pulsed Radar Architecture with a High Range Resolution

“…Depending on the type of laser source employed, the radars adopting the microwave photonics technology can be divided into a pulsed radar applying a mode-locked laser (MLL) and a frequency modulated continuous-wave (FMCW) radar using continuous-wave (CW) laser [8][9][10][11][12]. A pulsed radar using an MLL can detect the lower radar cross-section (RCS) targets with the same power consumption compared to an FMCW radar.…”

“…Therefore, in order to prevent the generation of thermal noise, an additional cooling system is required, which results in increasing the volume of the system [14][15][16][17]. For these reasons, the previous studied of the photonic-based pulsed radars with an MLL is mainly focused on for long-range target detection, and the acquisition of high-resolution ISAR images has been studied in photonic-based FMCW radars with a CW laser source [8,9,[18][19][20][21][22][23][24]. According to the results of the previous studies, the photonic-based pulsed radar with MLL can replace the conventional electronic-based shipborne radar or airborne radar, and the photonic-based FMCW radar with CW laser can be applied to automobiles, distance measurement, or missile fuses.…”