Performance assessment techniques for doppler radar physiological sensors

With the development of high speed digital processor and solid state power electronics, more flexible waveforms become feasible to achieve by modern radar systems. In fact, the choice of waveforms has a significant impact on the performance of radar systems. In this paper, we review the conventional radar waveform design as well as explore the new generation of waveforms via different theoretical methods, including the most recent wavelet based waveforms. It is shown that the waveform design supports the radar advancement for more intelligent and divergent applications. In this endeavor, radar waveform design plays an even more important role in reaching specific purposes, in addition to range and speed detections, and further improves the performance and application scopes of radar systems.

Recently, European Union advocates the smart Solid-State Lighting (SSL). The key factors are a smart-control scheme and an interaction with other networks, such as communication networks and traffic monitoring sensor networks. Public lighting represents a significant share of city total electricity costs, accounting for up to 60% of the budget. The adoption and deployment of new technologies, such as SSL that is based on Light-Emitting Diodes (LED), offer great opportunities to improve efficiencies and reduce costs. When combined with smart light management systems, SSL can save up the electricity used for lighting and significantly reduce energy and maintenance costs compared to current lighting installations. Moreover, streetlights are the infrastructures erecting beside or in the middle of the streets, so they seem to be the ideal observers of the traffic situations. Even though, other functional sensors, e.g., for measuring temperatures, CO2 and even particulate matter 2.5 (PM2.5), could be integrated in the smart-streetlights. Nowadays there are no sensors embedded in commercial available streetlights, except for the infrared motion sensor used only for pedestrian detection since their range is limited to about 10 meters, as well as there are limited networking capabilities, both in data-rate and functionalities, e.g. it is possible the dimming of only the entire file of streetlights. Hence, the idea to develop aWireless Sensor Front-End (WSFE), which is capable of working as motion sensor, namely a Doppler radar sensor, to monitor the road traffic as well as transceiver to communicate with the other network nodes. Such kind of WSFE could enable many streetlights futures, for example the lighting can be adapted to the traffic conditions and the presence of pedestrians on the sideways. Meanwhile, the communication function can build up a wireless network that can be used to manage the streetlight infrastructure and to collect information on traffic conditions, sensor reading, network status and so on. This thesis proposes a 24GHz 4-channel Phased-Array (Ph-A) front-end for smart-streetlight applications. The design exploits a 90nm Complementary Metal-Oxide-Semiconductor (CMOS) technology to benefit of the low-cost offered by CMOS technology. The architecture of the selected front-end allows the implementation of transceivers as well as Doppler radar sensors. Furthermore, the Ph-A technology is applied to the Doppler radar sensor in order to realizemulti-lane road scanning and pedestrian detection. The intercommunication between streetlights is based on a time-sharing mechanism and uses the same FE reconfigured as transceiver.[...]

Target detection is a mandatory task of radar system so that the radar system performance is mainly determined by its detection rate. Constant False Alarm Rate (CFAR) is a detection algorithm commonly used in radar systems. This method is divided into several approaches which have different performance in the different environments. Therefore, this paper proposes an ensemble neural network based classifier with a variation of hidden neuron number for classifying the radar environments. The result of this research will support the improvement of the performance of the target detection on the radar systems by developing such an adaptive CFAR. Multi-layer perceptron network (MLPN) with a single hidden layer is employed as the structure of base classifiers. The first step of this research is the evaluation of the hidden neuron number giving the highest accuracy of classification and the simplicity of computation. According to the result of this step, the three best structures are selected to build an ensemble classifier. On the ensemble structure, all of those three MLPN outputs then be collected and voted for getting the majority result in order to decide the final classification. The three possible radar environments investigated are homogeneous, multiple-targets and clutter boundary. According to the simulation results, the ensemble MLPN provides a higher detection rate than the conventional single MLPNs. Moreover, in the multiple-target and clutter boundary environments, the proposed method is able to show its highest performance.

Radar based detection of human targets behind walls or in dense urban environments is an important technical challenge with many practical applications in security, defense, and disaster recovery. Radar reflections from a human can be orders of magnitude weaker than those from objects encountered in urban settings such as walls, cars, or possibly rubble after a disaster. Furthermore, these objects can act as secondary reflectors and produce multipath returns from a person. To mitigate these issues, processing of radar return data needs to be optimized for recognizing human motion features such as walking, running, or breathing. This paper presents a theoretical analysis on the modulation effects human motion has on the radar waveform and how high levels of multipath can distort these motion effects. From this analysis, an algorithm is designed and optimized for tracking human motion in heavily clutter environments. The tracking results will be used as the fundamental detection/classification tool to discriminate human targets from others by identifying human motion traits such as predictable walking patterns and periodicity in breathing rates. The theoretical formulations will be tested against simulation and measured data collected using a low power, portable see-through-the-wall radar system that could be practically deployed in real-world scenarios. Lastly, the performance of the algorithm is evaluated in a series of experiments where both a single person and multiple people are moving in an indoor, cluttered environment.

Influence of plasticizer configurational changes on the dielectric characteristics of highly plasticized poly(vinyl chloride)

The role of the Royal Navy has changed dramatically since the end of the Cold War. Ships and personnel are now expected to fulfil a wider range of possible missions in theatres all over the world. Consequently ship's radar systems are now expected to give a high level of performance in regions that include the Middle East and the Eastern Mediterranean, despite being originally designed to operate predominately in the North Atlantic. The problem is that the local scenario and environmental conditions can dramatically affect radar system performance in two important ways. Firstly the environment can change the way that energy propagates outwards from the radar leading to large variations in target and clutter strength between different locations. Secondly these variations are often hidden by automatic threshold changes that reduce sensitivity to prevent the radar picture from becoming cluttered. This can give the false impression that the radar is operating optimally and could prevent ship's personnel from adapting their tactics to fit to the local situation. This paper outlines an updated model that is compared to real data in ducting conditions. The model is used to examine radar performance in littoral scenarios and to estimate sea state and duct strength from real radar data. The ultimate aim is to combine information collected by the ship's surveillance radar with modelling to allow ship's personnel to monitor the effect of the local environment on radar performance.

The radar system designer is constrained by limited budgets for resources such as cost, weight, prime power, and volume. Under these constraints, the designer attempts to maximize the radar system performance. After selecting the operating frequency band and the basic design approach, the primary way to improve radar performance is to increase the average radiated power (P) and the antenna aperture area (A). Search radar performance scales with the power-aperture product PA, track radar performance scales in proportion to PA/sup 2/, and fire control radar performance scales as PA/sup 3/ of PA/sup 4/. After allocating resources to all other sub-systems (e.g. computers and signal processors), the system designer must determine how to balance resource allocation between P and A. This analysis determines the optimal allocation of the critical resource that is exhausted before others. If the resource cost of P and A are linear and independent, the analysis shows that for a search radar the critical resource should be divided equally between P and A. For a track radar, one-third of the critical resource should be allocated to P and two-thirds to A. For a fire control radar, one-fourth or one-fifth of the critical resource should be allocated to P, with the remainder allocated to A. The analysis also provides results to optimally balance P and A in the case where the resource costs are non-linear functions. The appendix reviews the relationship between P, A, and radar performance.

In this paper, a detailed description of the roadmap to transform four individual CODAR SeaSonde high-frequency (HF) radars into an integrated HF radar network operated by Puertos del Estado (Madrid, Spain) is provided. To assess the maturation process into a fully operational status, the system must evolve via an implementation of phased approaches, including: homogenization of maintenance practices, quality control checks in real time, standardization of data access, and development of customized visualization tools. Additionally, continuous validation works with independent in situ sensors are required to provide upper bounds on both radial and total radar current measurement accuracies. Consistent correlation coefficients and uncertainty values emerge in the range of 0.31–0.81 and 8–22 cm/s, respectively, for the remotely estimated velocities. Complementarily, a dedicated online website has been developed to operationally monitor radar system health in real time. This automated quality control application analyzes a number of diagnose parameters to obtain estimates of their standard ranges and evaluate radar site performance according to them. Abrupt changes, gradual degradation, and/or failure problems can be easily detected, triggering alerts for troubleshooting. Once a good performance of HF radar systems is ensured, 2-D surface current maps are used for a broad range of practical applications, i.e., search-and-rescue operations, oil spill response, or the rigorous skill assessment of an operational ocean forecasting system such as Iberia–Biscay–Ireland (IBI), implemented within the frame of the Copernicus Marine Environment Monitoring Service.

This paper reviews the remote sensing of waves and turbulence in statically stable atmospheric layers, utilizing sodar and microwave radar echoes from the small-scale inhomogeneities in gaseous refractive index caused by localized fluctuations in temperature, humidity, and velocity. Scattering theory and sounding methodology are reviewed briefly, and the relative performance of typical radar and sodar systems compared. The main section of the paper takes the form of a summary and discussion of experimental progress since 1969, showing how the echo patterns obtained may be applied to the interpretation of multiple layering, gravity waves, internal fronts and the details of dynamic instability and the genesis of turbulence in stably stratified shear layers. In addition, methods for the measurement of the intensity of the small-scale (∼ λ/2) variability of wind, temperature and water vapor from the observed radar or sodar echo intensities, and the use of Doppler techniques for the measurement of mean velocity and turbulence are discussed.

The reliable prediction of RF system performance depends on the morphology of the tropospheric environment. For instance, the performance of systems, operating at frequencies above 10 GHz, are particularly affected by hydrometeor scattering and molecular resonance processes occurring in the moist and unstable sea surface air. In addition, the turbulent transport processes occurring near the sea surface have a major influence in predicting communication and radar system performance. Evaporation ducts arise from such processes near the sea surface and therefore their characterization require humidity gradient measurements which are difficult to obtain at low heights. Successful implementations of Parabolic Equation Modelling (PEM) for predicting propagation rely on knowing the refractive index at very low heights.

Accelerated investments on wind power projects because of the great demand for renewable energy are increasing the concerns about deteriorating effects of wind turbines on the performance of civil and military radar, navigation and communications systems. In this study, the authors introduce a preliminary set of analysis for assessing the performance of electronic systems such as radar, communications and navigation systems and the degrading/deteriorating effects of wind turbines. The analysis quantifies the performance degradation in the electronic systems. The proposed study can be used as a tool by decision makers in the planning and designing phases of both electronic systems and wind turbines to reduce the adverse effects of the wind farms on the mentioned systems.

The Pocket Radar Guide is a concise collection of key radar facts and important radar data that provides you with necessary radar information when you are away from your office or references. It includes statements and comments on radar design, operation, and performance; equations describing the characteristics and performance of radar systems and their components; and tables with data on radar characteristics and key performance issues. It is intended to supplement other radar information sources by providing a pocket companion to refresh memory and provide details whenever you need them such as in meetings, while traveling, or in the field.

The focus of this paper is (i) to derive a suitable dynamic model for a self-reconfigurable pavement sweeping robot PANTHERA and (ii) to design a robust controller for the same to tackle uncertainties stemming from the reconfiguration process, external disturbances and from actuator saturation. To meet the first objective, an Euler-Lagrangian dynamic model is proposed to incorporate the effects of configuration changes on the system dynamics. Based on this model, the second objective is met via designing a singular perturbation based robust controller which can tackle the aforementioned uncertainties without violating the actuation limits. To circumvent the vulnerability toward actuator saturation, the proposed controller is built on contraction theory, which, compared to a conventional Lyapunov theory based design, allows to improve closed-loop tracking performance without reducing the singular perturbation parameter. Experimental results on the PANTHERA reconfigurable robot validate the effectiveness of the proposed controller over the state of the art.

Design, synthesis and biological evaluation of Nucleosidic CD99 inhibitors that selectively reduce Ewing sarcoma viability.

The microenvironment around the chromophores and its changes due to the association states in C-phycocyanin isolated from the cyanobacterium Mastigocladus laminosus