Monitoring of Civil Infrastructures by Interferometric Radar: A Review (original) (raw)

Experimental utilization of interferometric radar techniques for structural monitoring

Structural Control and Health Monitoring, 2008

This paper presents a new surveying technique that can be employed with hardly reachable structures or extensive structures. The technique is based on an interferometric radar device, which can be positioned up to 2 km away from the structure to be examined and can record displacement measurements with a sampling frequency of up to 100 Hz and an accuracy of 0.1 mm. The results given by the radar are compared with those given by a set of three accelerometers on a test structure (namely, a steel cable-stayed footbridge) for three different loads: a symmetric dynamic load, an eccentric dynamic load and a symmetric quasi-static load.

Monitoring Critical Infrastructure Exposed to Anthropogenic and Natural Hazards Using Satellite Radar Interferometry

Proceedings - 3rd Congress in Geomatics Engineering - CIGeo, 2021

Synthetic Aperture Radar Interferometry (InSAR) is a remote sensing technique very effective for the measure of smalldisplacements of the Earth’s surface over large areas at a very low cost as compared with conventional geodetictechniques. Advanced InSAR time series algorithms for monitoring and investigating surface displacement on Earth arebased on conventional radar interferometry. These techniques allow us to measure deformation with uncertainties of 1mm/year, interpreting time series of interferometric phases at coherent point scatterers (PS) without the need for humanor special equipment presence on the site. By applying InSAR processing techniques to a series of radar images over thesame region, it is possible to detect line-of-sight (LOS) displacements of infrastructures on the ground and therefore identifyabnormal or excessive movement indicating potential problems requiring detailed ground investigation. A major advantageof this technology is that a single radar image can ...

Using Ground Radar Interferometry for Precise Determining of Deformation and Vertical Deflection of Structures

IOP Conference Series: Earth and Environmental Science

The paper describes possibilities of the relatively new technics -ground based radar interferometry for precise determining of deformation of structures. Special focus on the vertical deflection of bridge structures and on the horizontal movements of high-rise buildings and structural objects is presented. The technology of ground based radar interferometry can be used in practice to the contactless determination of deformations of structures with accuracy up to 0.01 mm in real time. It is also possible in real time to capture oscillations of the object with a frequency up to 50 Hz. Deformations can be determined simultaneously in multiple places of the object, for example a bridge structure at points distributed on the bridge deck at intervals of one or more meters. This allows to obtain both overall and detailed information about the properties of the structure during the dynamic load and monitoring the impact of movements either individual vehicles or groups. In the case of high-rise buildings, it is possible to monitor the horizontal vibration of the whole object at its different height levels. It is possible to detect and determine the compound oscillations that occur in some types of buildings. Then prevent any damage or even disasters in these objects. In addition to the necessary theory basic principles of using radar interferometry for determining of deformation of structures are given. Practical examples of determining deformation of bridge structures, water towers reservoirs, factory chimneys and wind power plants are also given. The IBIS-S interferometric radar of the Italian IDS manufacturer was used for the measurements.

Monitoring of Horizontal Movements of High-Rise Buildings and Tower Transmitters by Means of Ground-Based Interferometric Radar

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences

The paper describes possibilities of the relatively new technicsground based radar interferometry for precise determining of deformation of structures. Special focus on the horizontal movements of high-rise buildings and on the tower transmitters is presented. The technology of ground based radar interferometry can be used in practice to the contactless determination of deformations of such structures with accuracy up to 0.01 mm in real time. It is also possible to capture oscillations of the object with a frequency up to 50 Hz in real time. Deformations can be determined simultaneously in multiple places of the object, for example in the case of high-rise buildings it is possible to monitor the horizontal vibration of the whole object at its different height levels intervals of one or more meters. It is possible to detect and determine the compound oscillations that occur in some types of such buildings. This allows to obtain both overall and detailed information about the properties of the structure during its dynamic load e.g. by wind. Then prevent any damage or even disasters in these objects. In addition to the necessary theory basic principles of using radar interferometry for determining of deformation of structures are given. Practical examples of determining of horizontal movements of high-rise building and tower transmitter are also given. The IBIS-S interferometric radar of the Italian IDS manufacturer was used for the measurements.

An experimental comparison of interferometric radar vs. accelerometers for monitoring of large structures

2007 European Radar Conference, 2007

An interferometric SFCW radar has been recently proposed as an equipment for dynamic testing/monitoring of structures like bridges, towers, buildings and so on. These operations are currently performed by networks of accelerometers. In this paper, the authors report the results of a monitoring on a steel cable-stayed footbridge and a comparison between the two measurement techniques. As the radar measures displacements and the accelerometers measure accelerations, a preliminary discussion about signals and noise is necessary.

Structural health monitoring of bridges using terrestrial radar interferometry

2015

Civil engineering structures are extremely sensitive at influence of outdoor conditions. Most often these are the influence of wind, sunshine, temperature changes of the surrounding and at least the influence of the own or other loading. According to resonance of the structure with the surrounding is coming to vibration and oscillation in relative high frequency interval (0.1 Hz-100.0 Hz). These phenomena significantly could affect the static and dynamic characteristics of structures, their safety and functionality. The paper brings an example of monitoring these phenomena. The object of monitoring is the Danube Bridge Apollo in Bratislava, which main steel structure was monitored by acceleration sensors at the frequency level up to 10 Hz. The main topic of the paper is the analysis of dynamic behaviour of structure using spectral analysis method. The usage of Fourier Transform is described, own frequencies and amplitudes of structure oscillation are calculated.

The Interferometric Use of Radar Sensors for the Urban Monitoring of Structural Vibrations and Surface Displacements

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2016

In this paper, we propose a combined use of real aperture radar (RAR) and synthetic aperture radar (SAR) sensors, within an interferometric processingchain, to provide a new methodology for monitoring urban environment and historical buildings at different temporal and spatial scales. In particular, ground-based RAR measurements are performed to estimate the vibration displacements and the natural oscillation frequencies of structures, with the aim of supporting the understanding of the building dynamic response. These measurements are then juxtaposed with ground-based and space-borne SAR data to monitor surface deformation phenomena, and hence, point out potential risks within an urban environment. In this framework, differential interferometric SAR algorithms are implemented to generate short-term (monthly) surface displacement and long-term (annual) mean surface displacement velocity maps at local (hundreds m 2) and regional (tens km 2) scale, respectively. The proposed methodology, developed among the activities carried out within the national project Programma Operativo Nazionale MASSIMO (Monitoraggio in Area Sismica di SIstemi MOnumentali), is tested and discussed for the ancient structure of Saint Augustine compound, located in the historical center of Cosenza (Italy) and representing a typical example of the Italian Cultural Heritage.