High speed photography technique for measuring impact strength of porous concrete

In this study, an impact strength measurement method based on high speed photography, that has been developed for testing porous concrete, was introduced. In the experiments, a drop weight impact test set-up instrumented with a high speed camera was used. The impact strength analyses were conducted using impedance mismatch method, where the wave...

A discrete-time channel simulator driven by measured scattering functions

In-situ measurements of the scattering function are used to drive a channel simulator developed in the context of underwater acoustic telemetry. Two operation modes of the simulator are evaluated. A replay mode is accomplished by interpolation of measured impulse responses. A second, stochastic mode delivers multiple realizations of a given...

Integrated Optoelectronic Probe Including a Vertical Cavity Surface Emitting Laser for Laser Doppler Perfusion Monitoring

An integrated optoelectronic probe with small dimensions, for direct-contact laser Doppler blood flow monitoring has been realized. A vertical cavity surface emitting laser (VCSEL), and a chip with photodetectors and all necessary electronics are integrated in a miniature probe head connected to a laptop computer. The computer sound processor is...

Development of Signal Processing Algorithms for High Resolution Airborne Millimeter Wave FMCW SAR

For airborne earth observation applications, there is a special interest in lightweight, cost effective, imaging sensors of high resolution. The combination of Frequency Modulated Continuous Wave (FMCW) technology and Synthetic Aperture Radar (SAR) techniques can lead to such a sensor. In this paper, a developed algorithm for SAR imaging that...

The development of a SAR dedicated navigation system: from scratch to the first test flight: 2004BU1-RE

In this paper, the authors propose to describe the development process of a navigation system, concerning Syntectic Aperture Radar (SAR) applications, starting from the motivation for the sensor selection and finalizing with the first flight-test results. Sensors selection was one of the first steps in the design. Motivations for the...

Shape and Doppler correction for a towed sonar array

Anti Submarine Warfare (ASW) is more and more focused toward shallow water environments. Many complications have come up for ASW sonar performance as a result of this. The problem that is tackled in this article is the performance loss due to the shape and motion of the sonar during a maneuver. Standard beamforming in towed sonar arrays is based...

Laser-induced acoustic landmine detection with experimental results on buried landmines

Acoustic landmine detection (ALD) is a technique for the detection of buried landmines including non-metal mines. Since it gives complementary results with GPR or metal detection, sensor fusion of these techniques with acoustic detection would give promising results. Two methods are used for the acoustic excitation of the soil: laser excitation...

Human walking estimation with radar

Radar can be used to observe humans that are obscured by objects such as walls. These humans cannot be visually observed. The radar measurements are used to animate an obscured human in virtual reality. This requires detailed information about the motion. The radar measurements give detailed information about the movements of the human body...

Radon transforms and time-frequency representations for ISAR motion compensation and imaging

The use of the Radon transform and the Wigner-Radon power spectrum for ISAR motion compensation is described. It is shown that the local Radon power spectrum is closely related to the Cohen's class of quadratic time-frequency representations in a similar way as the Radon and Fourier transform are related. The peak of the local Radon transform is...

Development of fiber optic sensors at TNO for explosion and shock wave measurements

Fiber Optic sensors are found to be very suitable for explosion and shock wave measurements because they are immune to Electromagnetic Interference (EMI). In the past few years, TNO has developed a number of sensor systems for explosion and shock wave measurements in which the optical fiber is a vital component. This paper presents a survey of...

Development of an example flow test object and comparison of five of these test objects, constructed in various laboratories

Doppler test objects are used to characterise Doppler systems, both stand-alone systems and the Doppler part of so-called duplex scanners. The aim of the project partially presented here is the development and validation of an example of a Doppler test object fulfilling the requirements of the IEC 1685. The project has been carried out by nine...

Multiple hypothesis clustering in radar plot extraction

False plots and plots with inaccurate range and Doppler estimates may severely degrade the performance of tracking algorithms in radar systems. This paper describes how a multiple hypothesis clustering technique can be applied to mitigate the problems involved in plot extraction. The measures of confidence for each hypothesis are based on fuzzy...

Field test of a lidar wind profiler

Atmospheric eddies, which have slightly different properties than their environment and are believed to be transported by the wind (Taylor's hypothesis), are used as tracers for remote wind measurements with a fast incoherent lidar. Horizontal measurements, parallel with the wind, have shown that the atmospheric structures can be traced in space...

Doppler haematotachographie: interpretatieproblemen env nieuwe mogelijkheden