Jaime Calvo-Gallego

Traffic Surveillance System Based on a High-Resolution Radar

Traffic surveillance is an important civilian application of radars. The current high-resolution radars give new opportunities so that the traffic application may be redefined. In this paper, a traffic scenario with a high-resolution radar is presented. A range-bin alignment method, the Global Range Alignment, which comes from the focusing techniques in inverse synthetic aperture radar, is applied to obtain further capabilities than the usual velocity measurement: distinction between vehicle types via length estimation and adequate management in situations with simultaneous targets. Preliminary results from a real scenario using a high-resolution linear frequency-modulated continuous-wave millimeter-wave radar are shown.

Motion compensation for ISAR based on the shift-and-convolution algorithm

ISAR (inverse synthetic aperture radar) is a coherent technique that obtains images of targets by processing the echoes returned during the dwell time. A higher angular resolution than the antenna beamwidth may be obtained. In this paper we report high resolution ISAR images, which have been obtained from data captured by a millimeter-wave LFMCW (linear frequency modulated continuous wave) radar. The target translational motion compensation is achieved by means of a new parametric algorithm, which makes use of the shift-and-convolution technique. This image autofocusing algorithm is compared with prominent point processing (PPP) and phase gradient autofocus (PGA). Simulated and real data from the millimeter-wave LFMCW radar are used to verify the proposed technique, although the method is also applicable to any kind of coherent radar.

I3WSN: Industrial Intelligent Wireless Sensor Networks for indoor environments

Sensor Web Enablement (SWE) technologies have been successfully applied to a great variety of outdoor scenarios but, in practical terms, little effort has been applied for indoor environments, and even less in the field of industrial applications. This article presents an intelligent SWE application for an indoor and industrial scenario, with the aim of improving and increasing the levels of human safety. The base low-level architecture is built on top of wireless sensor networks (WSN) connected to a Sensor Observation Service (SOS). Higher layers in the architecture include services that make real time decisions based on the collected data. Both simulation and experimental results are presented. The paper shows the viability of our approach in terms of performance, scalability, modularity and safety.

A shift-and-convolution technique for high-resolution radar images

Theoretical and experimental results of a new method able to obtain images with high-resolution radars (HRRs) are presented in this paper. This algorithm does not need the data-phase information of the signal reflected by targets; it only uses the extracted noncoherent data. The proposed procedure works on real time, and it is compatible with the scanning and tracking radar functions. The technique consists of a modification and adaptation of algorithms used for the synchronization of the actual digital communication systems. Experimental results have been obtained with ARIES radar, a surface marine and coast surveillance HHR developed by INDRA SISTEMAS S.A. in collaboration with the Technical University of Madrid. The Spanish Ministry of Defence founded this research.

SIMPLE TRAFFIC SURVEILLANCE SYSTEM BASED ON RANGE-DOPPLER RADAR IMAGES

A simple tra-c surveillance system based on the extraction of features from range-Doppler radar images is addressed. The concept exploits the High-Resolution Radars (HRR) properties. Speciflcally, a procedure is proposed to obtain some features from the HRR non-cooperative targets to enable their classiflcation. These features are the distance, radial velocity, radial longitudinal dimension of the target, its integrated range-Doppler image based on a group of range-Doppler frames from each target, and both the coherent and non-coherent integrated range proflles. Experimental results from real scenarios using a high-resolution Linear-Frequency-Modulated Continuous-Wave (LFMCW) millimetre-wave radar are shown.

Focused ISAR images of maritime targets using a high resolution LFMCW millimeter-wave radar

The generation of high resolution ISAR (inverse synthetic aperture radar) images is reaching protagonism at the present time. A major application is coast surveillance. The recognition and the identification of maritime targets are important tasks. In this paper experimental results of ISAR images of maritime targets are reported. The data were captured with an LFMCW (linear frequency modulated continuous wave) millimeter-wave radar. High resolution ISAR images are obtained, since a great bandwidth (1 GHz) is transmitted. In ISAR the target motion can degrade the quality of the final images and motion compensation algorithms are necessary to improve the focus of these images. An autofocusing technique based on the shift-and-convolution algorithm is used to compensate the translational target motion and a two-phase algorithm (slant range rotation compensation (SRRC) and cross range rotation compensation (CRRC)) is used to correct the migration through resolution cells (MTRC) associated with the target rotation. The effectiveness of the focusing techniques is verified with simulated and real (maritime targets) radar data and compared with the standard range-Doppler algorithm (RDA)

Monitoring road traffic with a high resolution LFMCW radar

The current development of the high resolution concept allows to redefine standard applications of radars, like the measurement of the motion parameters of road traffic. High resolution radars may be used to monitor the road traffic. In this paper, live captures from a high resolution linear frequency modulated continuous wave (LFMCW) millimeter-wave radar are shown. For the estimation of the dynamics of the simultaneously illuminated targets, two approaches are described. The first one is a tracking-based technique of the vehicle echoes in the range-Doppler-slow time domain. The second one uses a range bin alignment technique, extracted from the inverse synthetic aperture radar (ISAR) world. This second approach works in the range profile domain. Both algorithms give similar results in the estimation of the speed of the vehicles. However, there are some divergences in the estimates of the accelerations. We hope that both algorithms may be useful for the future traffic surveillance systems.

Sub-Micron Gate Length Field Effect Transistors as Broad Band Detectors of Terahertz Radiation

We report on room temperature non-resonant detection of terahertz radiation using strained Silicon MODFETs with nanoscale gate lengths. The devices were excited at room temperature by an electronic source at 150 and 300 GHz. A maximum intensity of the photoresponse signal was observed around the threshold voltage. Results from numerical simulations based on synopsys TCAD are in agreement with experimental ones. The NEP and Responsivity were calculated from the photoreponse signal obtained experimentally. Those values are competitive with the commercial ones. A maximum of photoresponse was obtained (for all devices) when the polarization of the incident terahertz radiations was in parallel with the fingers of the gate pads. For applications, the device was used as a sensor within a terahertz imaging system and its ability for inspection of hidden objects was demonstrated.

Effect of the gate scaling on the analogue performance of s-Si CMOS devices

In this contribution, we present a detailed study of the analogue performance of deep submicron strained n-channel Si/SiGe (s-Si) MOSFETs. The study was carried out using a 2D device simulator based on the hydrodynamic model and the impedance field method to self-consistently obtain the current noise at the devices terminals. The analysis focused on the possible benefits of the gate scaling on the ac and noise performance of the transistor for low-power applications while keeping constant the oxide thickness equal to 2 nm to guarantee negligible level of the gate tunnel current. For a drain to source bias of 50 mV, it was found that a pure scaling of the transistors gate length under 32 nm is detrimental for subthreshold operation in terms of the subthreshold slope (S) and transconductance (gm) but would lead to reasonably low values of the minimum noise figure (NFmin). For the sake of comparison, SOI MOSFETs with the same layout and operating under the same conditions were simulated. The SOI MOSFETs showed better immunity against the gate scaling in terms of S than the s-Si MOSFETs, but lower values of gm and a higher value of NFmin at the same level of the drain current. Finally, the devices have been studied in the saturation region for a drain to source bias of 1 V. In this region, it was found that the dependence of the current level SOI or s-Si MOSFET may outperform its counterparts.

Accurate multi-target surveillance system over wide areas

The article presents an accurate system for surveillance purposes of multiple targets in wide areas. The surveillance system is based on a GB-ROSAR (Ground-Based-Rotating Synthetic Aperture Radar). It is a fixed radar with the ability of obtaining images by synthesizing the radiating aperture by a circular movement of the antenna. The prototype makes use of FM-CW (Frequency-Modulated Continuous-Wave) signals, operating in millimeter wave bands. The system has been developed with low cost devices. The objective of this work is to show, through simulations and experimental results, the real possibilities of this type of systems in the setting of precise surveillance of several targets simultaneously over wide areas. This study contains the design and construction of the proposed surveillance system, the implemented signal processing, the obtained results and its interpretation, and the conclusions about this work.