Devis Dei

Non-Contact Detection of Breathing Using a Microwave Sensor

In this paper the use of a continuous-wave microwave sensor as a non-contact tool for quantitative measurement of respiratory tidal volume has been evaluated by experimentation in seventeen healthy volunteers. The sensor working principle is reported and several causes that can affect its response are analyzed. A suitable data processing has been devised able to reject the majority of breath measurements taken under non suitable conditions. Furthermore, a relationship between microwave sensor measurements and volume inspired and expired at quiet breathing (tidal volume) has been found.

Detection of Breathing and Heartbeat Through Snow Using a Microwave Transceiver

The potential of a continuous-wave microwave transceiver as a tool for detecting breathing and heartbeat of people buried in snow has been experimentally evaluated. The breathing has been clearly detected through a 1.8-m-thick snow barrier as well as through the 1.2-m-thick roof of an igloo dugout to simulate the experimental conditions of a human being trapped under an avalanche.

Remote Survey of the Leaning Tower of Pisa by Interferometric Sensing

The Leaning Tower of Pisa, one of the world-famous architectural marvels of Italian heritage, needs continuous surveying to assess its stability. In this letter, remote-sensing equipment recently developed by the authors, based on the principle of microwave radar interferometry, has been experimented to measure the frequency response of the Tower without requiring any contact with its structure. Wind and human traffic were used as natural excitation sources, allowing the natural frequencies of the first vibration mode of the Tower to be measured in the north-south and in the west-east directions. Modal shapes of the Tower vibrations were also obtained from data acquired by the radar.

An ultra-wideband high-dynamic range GPR for detecting buried people after collapse of buildings

An ultra wide band high dynamic range GPR radar - has been tested for buried victims detection. After a building collapse, for example due to an earthquake, the priority of search and rescue teams is to localize people trapped under debris. Several tools are available to help the detection of buried humans, such as micro-cameras, high sensitivity microphones, and so on. Many of these tools present some limitations such as low penetration depth and high susceptibility to external noises. In this paper the authors test the use of an Enhanced Ultra Wide Band (UWB), Continuous Wave Stepped Frequency (CW-SF) Ground penetrating radar as rescue equipment. The radar has been experimented both in controlled environment, and in a real test site, at the Fire-fighters Station of Pisa, Italy.

Landslide observation by ground-based SAR interferometry

A ground-based synthetic aperture radar (GB-SAR) system was installed for the observation and monitoring of post-landslide slope in Kurihara-city, Miyagi, Japan. The system is operated at 17 GHz (Ku-band) with a frequency bandwidth of 150 MHz. Horn antennas scan about 2 m horizontally to cover a large observation area and SAR processing is applied to achieve higher azimuth and range resolutions. In addition, the interferometric technique is used to detect very small changes on the target, resulting in the expected interferometer resolution of 0.1 mm. In 2011, the system operated from November to December to acquire preliminary results and to study the feasibility of the technique for monitoring landslide surface. During the period, major events on the landslide surface did not happen and, thus, no significant changes were detected by the GB-SAR system. However, it detected small movements at some locations approaching to the system that is likely caused by a snowfall. It demonstrates the capability of the GB-SAR technique in detecting very small changes on a target.

A reconfigurable stepped frequency GPR (GPR-R)

Ground Penetrating Radars are a unique and well known tool for soil investigation.

Development of a bore-head GPR for Horizontal Directional Drilling (HDD) equipment

ORFEUS is a Specific Targeted Research Project (STREP), partly funded by the EC, that started in November 2006. One of the objectives of the project was to design and develop a radar mounted on the drill head of Horizontal Directional Drilling (HDD) machines to provide a real-time indication, to the operator, of obstacles in the drill path. The system consists of a GPR control unit (housed in a drilling rod) and two UWB antennas. These can detect buried infrastructure that the bore-head may strike and verify a clearance zone around the drill string to ensure that new pipes may be installed with a minimum separation from adjacent plant. During the 3 year project, several key technical problems, mainly concerning electromagnetic and mechanical compatibility issues, have been solved. The system was finally tested both in experimental and operational sites. These tests confirmed the capability of the equipment to provide useful information on the obstacles in the drilling path; detection range has been evaluated to be sufficient to generate a warning message to the operator to allow corrective action to be taken, thus enabling HDD equipment to be used in greater safety.

A novel ground based multi bistatic radar for interferometric measurement of displacement vector

A novel ground based multi bistatic interferometric radar sensor has been realized in order to measure the three dimensional displacement vector of civil structures as buildings, bridges and towers.

Mitigation of narrowband interferences by means of a reconfigurable stepped frequency GPR system

This paper proposes a new technique for the mitigation of narrowband interferences by making use of an innovative stepped frequency Ground Penetrating Radar (GPR) system, based on the modulation of the integration time of the harmonic components of the signal. This can allow a good rejection of the interference signal without filtering out part of the band of the useful signal (which would involve a loss of information) and without increasing the power of the transmitted signal (which might saturate the receiver and make illegal the level of transmitted power). The price paid for this is an extension of the time needed in order to perform the measurements. We will show that this necessary drawback can be contained by making use of a prototypal reconfigurable stepped frequency GPR system.

Applications of a reconfigurable stepped frequency GPR in the chapel of the Holy Spirit, Lecce (Italy)

We present the first application in the field of a reconfigurable stepped frequency system. The system has been designed in collaboration between the Institute for Archaeological and Monumental Heritage IBAM-CNR Lecce the Department of. Electronics and Telecommuncations of the University of Florence and the Company Ingegneria dei Sistemi IDS S.p.A., Pisa. We show some results achieved in the chapel of the ex hospital of the Holy Spirit in Lecce and we compare them with the results obtained by using a commercial pulsed GPR system.