1,654 research outputs found
Airborne Wind Shear Detection and Warning Systems. Second Combined Manufacturers' and Technologists' Conference, part 1
The Second Combined Manufacturers' and Technologists' Conference hosted jointly by NASA Langley (LaRC) and the Federal Aviation Administration (FAA) was held in Williamsburg, Virginia, on October 18 to 20, 1988. The purpose of the meeting was to transfer significant, ongoing results gained during the second year of the joint NASA/FAA Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements
A novel satellite mission concept for upper air water vapour, aerosol and cloud observations using integrated path differential absorption LiDAR limb sounding
We propose a new satellite mission to deliver high quality measurements of upper air water vapour. The concept centres around a LiDAR in limb sounding by occultation geometry, designed to operate as a very long path system for differential absorption measurements. We present a preliminary performance analysis with a system sized to send 75 mJ pulses at 25 Hz at four wavelengths close to 935 nm, to up to 5 microsatellites in a counter-rotating orbit, carrying retroreflectors characterized by a reflected beam divergence of roughly twice the emitted laser beam divergence of 15 µrad. This provides water vapour profiles with a vertical sampling of 110 m; preliminary calculations suggest that the system could detect concentrations of less than 5 ppm. A secondary payload of a fairly conventional medium resolution multispectral radiometer allows wide-swath cloud and aerosol imaging. The total weight and power of the system are estimated at 3 tons and 2,700 W respectively. This novel concept presents significant challenges, including the performance of the lasers in space, the tracking between the main spacecraft and the retroreflectors, the refractive effects of turbulence, and the design of the telescopes to achieve a high signal-to-noise ratio for the high precision measurements. The mission concept was conceived at the Alpbach Summer School 2010
People tracking by cooperative fusion of RADAR and camera sensors
Accurate 3D tracking of objects from monocular camera poses challenges due to the loss of depth during projection. Although ranging by RADAR has proven effective in highway environments, people tracking remains beyond the capability of single sensor systems. In this paper, we propose a cooperative RADAR-camera fusion method for people tracking on the ground plane. Using average person height, joint detection likelihood is calculated by back-projecting detections from the camera onto the RADAR Range-Azimuth data. Peaks in the joint likelihood, representing candidate targets, are fed into a Particle Filter tracker. Depending on the association outcome, particles are updated using the associated detections (Tracking by Detection), or by sampling the raw likelihood itself (Tracking Before Detection). Utilizing the raw likelihood data has the advantage that lost targets are continuously tracked even if the camera or RADAR signal is below the detection threshold. We show that in single target, uncluttered environments, the proposed method entirely outperforms camera-only tracking. Experiments in a real-world urban environment also confirm that the cooperative fusion tracker produces significantly better estimates, even in difficult and ambiguous situations
Remote Sensing
This dual conception of remote sensing brought us to the idea of preparing two different books; in addition to the first book which displays recent advances in remote sensing applications, this book is devoted to new techniques for data processing, sensors and platforms. We do not intend this book to cover all aspects of remote sensing techniques and platforms, since it would be an impossible task for a single volume. Instead, we have collected a number of high-quality, original and representative contributions in those areas
Demonstration of quantum-enhanced rangefinding robust against classical jamming
In this paper we demonstrate operation of a quantum-enhanced lidar based on a
continuously pumped photon pair source combined with simple detection in
regimes with over 5 orders of magnitude separation between signal and
background levels and target reflectivity down to -52 dB. We characterise the
performance of our detector using a log-likelihood analysis framework, and
crucially demonstrate the robustness of our system to fast and slow classical
jamming, introducing a new protocol to implement dynamic background tracking to
eliminate the impact of slow background changes whilst maintaining immunity to
high frequency fluctuations. Finally, we extend this system to the regime of
rangefinding in the presence of classical jamming to locate a target with an 11
cm spatial resolution limited only by the detector jitter. These results
demonstrate the advantage of exploiting quantum correlations for lidar
applications, providing a clear route to implementation of this system in
real-world scenarios
Payload's sway angle measurement for container in the crane system based on remote sensing
The demand for a high quickly measuring angle in the port crane system should be
considered when the container has been transferred from one place to another place. It is
significant to build the feedback linking of payload's angle in the integrated crane system.
The value of accurate measurement of the angle can be used to optimize the crane control
system. In this context, the design and implementation of the experimental setup
associated with emulated cranes will be carried out. Several solutions for remote angle
measurement were considered one of the considered solutions being represented by
millimeter microwave radar sensors. Special developments of algorithms to calculate the
sway angle of payload or container were considered as so as the real-time processing
using Arduino Uno computation platform. The following objectives were successfully
reached.
1. Development of remote sensing system for payload's swing angle measurement
considering radars such the sensing devices;
2. Development of a novel angle algorithm measurement and real-time processing of
data;
3. Development of a prototype characterized by real-time processing and remote
detection capabilities considering short-range and long-range measurements, such as lidar
sensor or radar sensor.A demanda por um ângulo de medição rápido e alto no sistema de guindaste portuário
deve ser considerada quando o contêiner for transferido de um local para outro. É
significativo construir a ligação de feedback do ângulo da carga útil no sistema de
guindaste integrado. O valor da medição precisa do ângulo pode ser usado para otimizar
o sistema de controle do guindaste. Neste contexto, será realizada a concepção e
implementação da configuração experimental associada a gruas emuladas. Diversas
soluções para medição remota de ângulos foram consideradas uma das soluções
consideradas sendo representadas por sensores de micro-ondas milimetrados.
Desenvolvimentos especiais de algoritmos para calcular o ângulo de oscilação da carga
útil ou contêiner foram considerados, assim como o processamento em tempo real usando
a plataforma de computação Arduino Uno. Os seguintes objetivos foram alcançados com
sucesso.
1. Desenvolvimento de sistema de sensoriamento remoto para medição do ângulo de
oscilação da carga útil considerando radares como os dispositivos de detecção;
2. Desenvolvimento de um novo algoritmo de medição de ângulos e processamento de
dados em tempo real;
3. Desenvolvimento de um protótipo caracterizado por processamento em tempo real
e capacidade de detecção remota considerando medições de curto e longo alcance, como
sensor LIDAR ou sensor de radar
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