Advanced Methodologies of Active and Passive Ground-Based Imaging Radar for Environmental Monitoring

要約のみTohoku University佐藤源之課

Pedestrian–bus route and pickup location planning for emergency evacuation

Planning for a bus-based regional evacuation is essential for emergency preparedness, especially for hurricane or flood prone urban environments with large numbers of transit-dependent or transit-captive populations. This paper develops an optimization-based decision-support model for pedestrian–bus evacuation planning under bus fleet, pedestrian and bus routes, and network constraints. Aiming to minimize the evacuation duration time, an optimization model is proposed to determine the optimal pickup nodes for evacuees to assemble using existing pedestrian routes, and to allocate available bus fleet via bus routes and urban road network to transport the assembled evacuees between the pickup nodes and designated public shelters. The numerical examples with two scenarios based on the Sioux Falls street network from North Dakota (United States) demonstrates that this model can be used to optimize the evacuation duration time, the location of pickup nodes and bus assignment simultaneously. First published online 13 October 202

Bridge Monitoring Strategies for Sustainable Development with Microwave Radar Interferometry

The potential of a coherent microwave radar for infrastructure health monitoring has been investigated over the past decade. Microwave radar measuring based on interferometry processing is a non-invasive technique that can measure the line-of-sight (LOS) displacements of large infrastructure with sub-millimeter precision and provide the corresponding frequency spectrum. It has the capability to estimate infrastructure vibration simultaneously and remotely with high accuracy and repeatability, which serves the long-term serviceability of bridge structures within the context of the long-term sustainability of civil engineering infrastructure management. In this paper, we present three types of microwave radar systems employed to monitor the displacement of bridges in Japan and Italy. A technique that fuses polarimetric analysis and the interferometry technique for bridge monitoring is proposed. Monitoring results achieved with full polarimetric real aperture radar (RAR), step-frequency continuous-wave (SFCW)-based linear synthetic aperture, and multi-input multi-output (MIMO) array sensors are also presented. The results reveal bridge dynamic responses under different loading conditions, including wind, vehicular traffic, and passing trains, and show that microwave sensor interferometry can be utilized to monitor the dynamics of bridge structures with unprecedented spatial and temporal resolution. This paper demonstrates that microwave sensor interferometry with efficient, cost-effective, and non-destructive properties is a serious contender to employment as a sustainable infrastructure monitoring technology serving the sustainable development agenda

RADAR passif bistatique au moyen d’une Raspberry Pi4, une radio logicielle et du satellite sentinel-1 hackable

International audienceNous exploitons les signaux émis à intervalles connus et documentéssur le site Copernicus de l’ESA par les satellites Sentinel-1 pourune mesure au sol de RADAR passif bistatique. Deux antennes au sol,une antenne de référence qui observe le signal direct émis par lesatellite, et une seconde antenne de surveillance qui observe lesréflexions par les cibles illuminées par le satellite sontconnectées à un récepteur de radio logicielle pour collecter à5405 MHz les signaux de Sentinel-1. La détection de cibles àplusieurs kilomètres du récepteur est démontrée avec un systèmesimple composé d’une radio logicielle Ettus Research B210 et d’uneRaspberry Pi 4 programmée efficacement. La diversité spatialeintroduite par le mouvement du satellite le long de son orbitepermet de cartographier les cibles en distance et en azimut

FedRec++: Lossless Federated Recommendation with Explicit Feedback

With the marriage of federated machine learning and recommender systems for privacy-aware preference modeling and personalization, there comes a new research branch called federated recommender systems aiming to build a recommendation model in a distributed way, i.e., each user is represented as a distributed client where his/her original rating data are not shared with the server or the other clients. Notice that, besides the sensitive information of a specific rating score assigned to a certain item by a user, the information of a user's rated set of items shall also be well protected. Some very recent works propose to randomly sample some unrated items for each user and then assign some virtual ratings, so that the server can not identify the scores and the set of rated items easily during the server-client interactions. However, the virtual ratings assigned to the randomly sampled items will inevitably introduce some noise to the model training process, which will then cause loss in recommendation performance. In this paper, we propose a novel lossless federated recommendation method (FedRec++) by allocating some denoising clients (i.e., users) to eliminate the noise in a privacy-aware manner. We further analyse our FedRec++ in terms of security and losslessness, and discuss its generality in the context of existing works. Extensive empirical studies clearly show the effectiveness of our FedRec++ in providing accurate and privacy-aware recommendation without much additional communication cost

SDR-Implemented Passive Bistatic SAR System Using Sentinel-1 Signal and Its Experiment Results

International audience<p class="western" style="margin-bottom: 0cm; line-height: 100%; orphans: 0; widows: 0"&gtAfixed-receiver mobile-transmitter passive bistatic syntheticaperture radar (MF-PB-SAR) system, which uses the Sentinel-1 SARsatellite as its non-cooperative emitting source, has beendeveloped by using embedded software-defined radio (SDR) hardwarefor high-resolution imaging of the targets in a local area in thisstudy. Firstly, Sentinel-1 and the designed system are introduced.Then, signal model, signal pre-processing methods, and effectivetarget imaging methods are presented. At last, various experimentresults of target imaging obtained at different locations are shownto validate the developed system and the proposed methods. It wasfound that targets in a range of several kilometers can be wellimaged. <a href="https://www.mdpi.com/2072-4292/14/1/221/htm"&gt</a&gt</p&g

SDR-Implemented Passive Bistatic SAR System Using Sentinel-1 Signal and Its Experiment Results

A fixed-receiver mobile-transmitter passive bistatic synthetic aperture radar (MF-PB-SAR) system, which uses the Sentinel-1 SAR satellite as its non-cooperative emitting source, has been developed by using embedded software-defined radio (SDR) hardware for high-resolution imaging of the targets in a local area in this study. Firstly, Sentinel-1 and the designed system are introduced. Then, signal model, signal pre-processing methods, and effective target imaging methods are presented. At last, various experiment results of target imaging obtained at different locations are shown to validate the developed system and the proposed methods. It was found that targets in a range of several kilometers can be well imaged

SDR-Implemented Passive Bistatic SAR System Using Sentinel-1 Signal and Its Experiment Results

A fixed-receiver mobile-transmitter passive bistatic synthetic aperture radar (MF-PB-SAR) system, which uses the Sentinel-1 SAR satellite as its non-cooperative emitting source, has been developed by using embedded software-defined radio (SDR) hardware for high-resolution imaging of the targets in a local area in this study. Firstly, Sentinel-1 and the designed system are introduced. Then, signal model, signal pre-processing methods, and effective target imaging methods are presented. At last, various experiment results of target imaging obtained at different locations are shown to validate the developed system and the proposed methods. It was found that targets in a range of several kilometers can be well imaged

Deep Unfolded Gridless DOA Estimation Networks Based on Atomic Norm Minimization

Deep unfolded networks have recently been regarded as an essential way to direction of arrival (DOA) estimation due to the fast convergence speed and high interpretability. However, few consider gridless DOA estimation. This paper proposes two deep unfolded gridless DOA estimation networks to resolve the above problem. We first consider the atomic norm-based 1D and decoupled atomic norm-based 2D gridless DOA models solved by the alternating iterative minimization of variables, respectively. Then, the corresponding deep networks are trained offline after constructing the corresponding complete training datasets. At last, the trained networks are applied to realize the 1D DOA and 2D estimation, respectively. Simulation results reveal that the proposed networks can secure higher 1D and 2D DOA estimation performances while maintaining a lower computational expenditure than typical methods