Noncontact Vital Signs Detection

Human health condition can be accessed by measurement of vital signs, i.e., respiratory rate (RR), heart rate (HR), blood oxygen level, temperature and blood pressure. Due to drawbacks of contact sensors in measurement, non-contact sensors such as imaging photoplethysmogram (IPPG) and Doppler radar system have been proposed for cardiorespiratory rates detection by researchers.The UWB pulse Doppler radars provide high resolution range-time-frequency information. It is bestowed with advantages of low transmitted power, through-wall capabilities, and high resolution in localization. However, the poor signal to noise ratio (SNR) makes it challenging for UWB radar systems to accurately detect the heartbeat of a subject. To solve the problem, phased-methods have been proposed to extract the phase variations in the reflected pulses modulated by human tiny thorax motions. Advance signal processing method, i.e., state space method, can not only be used to enhance SNR of human vital signs detection, but also enable the micro-Doppler trajectories extraction of walking subject from UWB radar data.Stepped Frequency Continuous Wave (SFCW) radar is an alternative technique useful to remotely monitor human subject activities. Compared with UWB pulse radar, it relieves the stress on requirement of high sampling rate analog-to-digital converter (ADC) and possesses higher signal-to-noise-ratio (SNR) in vital signs detection. However, conventional SFCW radar suffers from long data acquisition time to step over many frequencies. To solve this problem, multi-channel SFCW radar has been proposed to step through different frequency bandwidths simultaneously. Compressed sensing (CS) can further reduce the data acquisition time by randomly stepping through 20% of the original frequency steps.In this work, SFCW system is implemented with low cost, off-the-shelf surface mount components to make the radar sensors portable. Experimental results collected from both pulse and SFCW radar systems have been validated with commercial contact sensors and satisfactory results are shown

Radar Technology

In this book “Radar Technology”, the chapters are divided into four main topic areas: Topic area 1: “Radar Systems” consists of chapters which treat whole radar systems, environment and target functional chain. Topic area 2: “Radar Applications” shows various applications of radar systems, including meteorological radars, ground penetrating radars and glaciology. Topic area 3: “Radar Functional Chain and Signal Processing” describes several aspects of the radar signal processing. From parameter extraction, target detection over tracking and classification technologies. Topic area 4: “Radar Subsystems and Components” consists of design technology of radar subsystem components like antenna design or waveform design

Experimental validation of a quasi-realtime human respiration detection method via UWB radar

In this paper, we propose a quasi-realtime human respiration detection method via UWB radar system in through-wall or similar condition. With respect to the previous proposed automatic detection method, the new proposed method assures competitive performance in the human respiration motion detection and effective noise/clutter rejection, which have been proved by experimental results in actual scenario. This new method has also been implemented in a UWB through-wall life-detection radar prototype, and its time consuming is about 2 s, which can satisfy the practical requirement of quasi-realtime for through-wall sequential vital sign detection. Therefore, it can be an alternative for through-obstacles static human detection in antiterrorism or rescue scenarios

Workshop on Radar Investigations of Planetary and Terrestrial Environments : February 7-10. 2005, Houston, Texas

Focuses on the capabilities of radar sounding and imaging systems to address issues such as: the subsurface geology and distribution of water on the Earth, Moon, Mars, and Europa, investigating the paleohydrology of planetary surfaces and identifying potential subsurface habitats capable of sustaining primitive life forms.Sponsored by: Lunar and Planetary Institute, National Aeronautics and Space Administration, Jet Propulsion Laboratory, Southwest Research Institute.Conveners: Essam Heggy., Lunar and Planetary Institute, Stephen Clifford, Lunar and Planetary Institute, Tom Farr, Jet Propulsion Laboratory, Cynthia Dinwiddie, Southwest Research Institute, Bob Grimm, Southwest Research Institute.PARTIAL CONTENTS: The Goldstone Solar System Radar: 1988-2003 Earth-based Mars Radar Observations / A. F. C. Haldemann, K. W. Larsen, R. F. Jurgens, and M A. Slade--Mapping Subsurface Stratigraphy and Anomalies in Iron-rich Volcanoclastics Using Ground-penetrating Radar: Potential for Shallow Sounding on Mars / E. Heggy, S. Clifford, R. Grimm, S. Gonzalez, D. Bannon, and D. Wyrick--Dielectric Map of the Martian Surface / E. Heggy and A. Pommerol--Surface Clutter Removal in Airborne Radar Sounding Data from the Dry Valleys, Antarctica / J. W. Holt, D. D. Blankenship, D. L. Morse, M E. Peters, and S. D. Kempf--Comparing Transient Electromagnetics and Low Frequency Ground Penetrating Radar for Sounding of Subsurface Water in Mars Analog Environments / J. A. Jernsletten and E. Heggy--The MARSIS Radar, Signal Simulation and Interpretation Using MOLA Topography Data / W. Koftnan, J. F. Nouvel, A. Herique, and J.-E. Martelal--A Phase Signature for Detecting Wet Structures in the Shallow Subsurface of Mars Using Polarimetric P-band SAR / Y: Lasne, Ph. Paillou, and J.-M Matezieux--Experimental Validation of the Mono and Bistatic Operating Mode of a GPR Dedicated to the Martian Subsurface Exploration / A. Le Gall, V. Ciorlelli, J. J. Berthelier, R. Ney, F. Dolon, and S. Bonoime

Step-frequency ground penetrating radar for agricultural soil morphology characterisation

Soil morphology plays a fundamental role in the vertical and lateral movements of solutes and water transport, providing knowledge regarding spatial distribution of its textural properties and subsurface dynamics. In this framework, the measured values of electrical conductivity are able to reveal the heterogeneity of soil that is present in a particular agricultural field and they are affected by more than one important physical characteristic: soil texture, organic matter, moisture content, and the depth of the clay pan. In the microwave region, these dynamics are known to exhibit a frequency dependent behaviour. This study explores the application of a Step Frequency Continuous Wave Ground Penetrating Radar (SFCW GPR) to shed light on the practical impact that these dependencies have on the imaging results, not only regarding the electrical characterisation of the subsurface morphology, but also in its correct interpretation. This information is of notable importance for determining water-use efficiency and planning precision-agriculture programs. The results clearly show visible and significant fluctuations of the amplitude levels, depending on the considered central frequency, demonstrating that the frequency dependence of electromagnetic properties of heterogeneous soil are significant and cannot be ignored if the aim is to properly define the subsurface attributes. The measurements also suggest that correlating the delineated variations might help in the identification of extended features and the classification of areas that possess similar properties in order to increase the confidence in monitoring soil resource

Aeronautical Engineering: A continuing bibliography with indexes (supplement 206)

This bibliography lists 422 reports, articles and other documents introduced into the NASA scientific and technical information system in October 1986

Aeronautical engineering: A continuing bibliography, supplement 122

This bibliography lists 303 reports, articles, and other documents introduced into the NASA scientific and technical information system in April 1980

Aeronautical engineering: A continuing bibliography with indexes (supplement 292)

This bibliography lists 675 reports, articles, and other documents recently introduced into the NASA scientific and technical information system database. Subject coverage includes the following: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment, and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics