50 research outputs found

    Guidebook on Detection Technologies and Systems for Humanitarian Demining

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    The aim of this publication is to provide the mine action community, and those supporting mine action, with a consolidated review and status summary of detection technologies that could be applied to humanitarian demining operations. This Guidebook is meant to provide information to a wide variety of readers. For those not familiar with the spectrum of technologies being considered for the detection of landmines and for area reduction, there is a brief overview of the principle of operation for each technology as well as a summary listing of the strengths, limitations, and potential for use of the technology to humanitarian demining. For those with an intermediate level of understanding for detection technologies, there is information regarding some of the more technical details of the system to give an expanded overview of the principles involved and hardware development that has taken place. Where possible, technical specifications for the systems are provided. For those requiring more information for a particular system, relevant publications lists and contact information are also provided

    Radar Technology

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    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

    Earth resources shuttle imaging radar

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    A report is presented on a preliminary design of a Synthetic Array Radar (SAR) intended for experimental use with the space shuttle program. The radar is called Earth Resources Shuttle Imaging Radar (ERSIR). Its primary purpose is to determine the usefulness of SAR in monitoring and managing earth resources. The design of the ERSIR, along with tradeoffs made during its evolution is discussed. The ERSIR consists of a flight sensor for collecting the raw radar data and a ground sensor used both for reducing these radar data to images and for extracting earth resources information from the data. The flight sensor consists of two high powered coherent, pulse radars, one that operates at L and the other at X-band. Radar data, recorded on tape can be either transmitted via a digital data link to a ground terminal or the tape can be delivered to the ground station after the shuttle lands. A description of data processing equipment and display devices is given

    Tracking moving objects in surveillance video

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    The thesis looks at approaches to the detection and tracking of potential objects of interest in surveillance video. The aim was to investigate and develop methods that might be suitable for eventual application through embedded software, running on a fixed-point processor, in analytics capable cameras. The work considers common approaches to object detection and representation, seeking out those that offer the necessary computational economy and the potential to be able to cope with constraints such as low frame rate due to possible limited processor time, or weak chromatic content that can occur in some typical surveillance contexts. The aim is for probabilistic tracking of objects rather than simple concatenation of frame by frame detections. This involves using recursive Bayesian estimation. The particle filter is a technique for implementing such a recursion and so it is examined in the context of both single target and combined multi-target tracking. A detailed examination of the operation of the single target tracking particle filter shows that objects can be tracked successfully using a relatively simple structured grey-scale histogram representation. It is shown that basic components of the particle filter can be simplified without loss in tracking quality. An analysis brings out the relationships between commonly used target representation distance measures and shows that in the context of the particle filter there is little to choose between them. With the correct choice of parameters, the simplest and computationally economic distance measure performs well. The work shows how to make that correct choice. Similarly, it is shown that a simple measurement likelihood function can be used in place of the more ubiquitous Gaussian. The important step of target state estimation is examined. The standard weighted mean approach is rejected, a recently proposed maximum a posteriori approach is shown to be not suitable in the context of the work, and a practical alternative is developed. Two methods are presented for tracker initialization. One of them is a simplification of an existing published method, the other is a novel approach. The aim is to detect trackable objects as they enter the scene, extract trackable features, then actively follow those features through subsequent frames. The multi-target tracking problem is then posed as one of management of multiple independent trackers

    Life-like Image Processing for Small Target Motion Detection in Cluttered Dynamic Environments

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    Discriminating targets moving against a cluttered background is a huge challenge for future robotic vision systems, let alone detecting a target as small as one or a few pixels. As a source of inspiration, insects are quite apt at searching for mates and tracking prey – which always appear as small dim speckles in the visual field. The exquisite sensitivity of insects for small target motion, as revealed recently, is coming from a class of specific neurons called small target motion detectors (STMDs). Some of the STMDs have also demonstrated direction selectivity which means these STMDs respond strongly only to their preferred motion direction. Build a quantitative STMD model is the first step for not only further understanding of the biological visual system, but also providing robust and economic solutions of small target detection for an artificial visual system. This research aims to explore STMD-based image processing methods for small target motion detection against cluttered dynamic backgrounds. The major contributions are summarized as follows. Three STMD-based neural models are proposed in this research named as directionally selective STMD(DSTMD), STMD Plus and Feedback STMD, respectively. The DSTMD systematically models and studies direction selectivity of the STMD neurons, meanwhile provides with unified and rigorous mathematical description. Specifically, in the DSTMD, a new correlation mechanism is introduced for direction selectivity via correlating signals relayed from two pixels. Then, a lateral inhibition mechanism is implemented on the spatial field for size selectivity of the STMD neurons. Finally, a population vector algorithm is used to encode motion direction of small targets. Extensive experiments showed that the proposed DSTMD not only is in accord with current biological findings, i.e. showing directional preferences, but also works reliably in detecting small targets against cluttered backgrounds. The STMD Plus is developed to discriminate small targets from small-target-like background features (named as fake features) by integrating motion information with directional contrast. More precisely, the STMD Plus is composed of four subsystems – ommatidia, motion pathway, contrast pathway and mushroom body. Compared to existing STMD-based models, the additional contrast pathway extracts directional contrast from luminance signals to eliminate false positive background motion. The directional contrast and the extracted motion information by the motion pathway are integrated in the mushroom body for small target discrimination. The experimental results demonstrated the significant and consistent improvements of the proposed visual system model over existing STMD-based models against fake features. The Feedback STMD is also designed to filter out fake features by introducing a new feedback mechanism. Specifically, the model output is first temporally delayed then applied to the previous neural layer to construct a feedback loop. By subtracting the feedback signal from the inputs of the STMDs, the background fake features are largely suppressed. Experimental results show that the developed feedback neural model achieves better performance than the existing STMD-based models in discriminating small targets from complex backgrounds

    Airborne Wind Shear Detection and Warning Systems. Second Combined Manufacturers' and Technologists' Conference, part 1

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    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

    Proceedings of the Augmented VIsual Display (AVID) Research Workshop

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    The papers, abstracts, and presentations were presented at a three day workshop focused on sensor modeling and simulation, and image enhancement, processing, and fusion. The technical sessions emphasized how sensor technology can be used to create visual imagery adequate for aircraft control and operations. Participants from industry, government, and academic laboratories contributed to panels on Sensor Systems, Sensor Modeling, Sensor Fusion, Image Processing (Computer and Human Vision), and Image Evaluation and Metrics

    Generating depth maps from stereo image pairs

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    Systems Theoretic Hazard Analysis (STPA) applied to the risk review of complex systems : an example from the medical device industry

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2013.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references.Traditional methods to identify and document hazards, and the corresponding safety constraints, are lacking in their ability to account for human, software and sub-system interactions in highly technical systems. STAMP, a systems-theoretic accident causality model, was created to overcome these limitations. The application of STAMP hazard analysis method STPA to five sub-systems of the Paul Scherrer Institute's experimental PROSCAN proton therapy system demonstrated how STPA can augment design and risk review of existing complex systems. Two of the five human controllers active in treatment delivery, two of the four process attributes controlled by the PROSCAN facility, and one of the four control loops that control the beam to target alignment attribute were analyzed. In doing so, the following contributions were made: - Analyzed the regulations currently in place in the US and Europe for the marketing of external beam radiotherapy devices and, more generally, medical devices that do not contain radioactive materials, concluding that STPA would be acceptable in both regulatory systems; - Provided experience in applying STPA to a complex device. Information on efficacy was derived by comparing STPA results with an existing safety assessment but a more formal counterpart is needed for stronger evidence. Information on learnability and usability was obtained when an informal workshop showed that system designers, in the course of one day, could be taught to use STPA to push their thinking about yet to be designed system elements; - Demonstrated the applicability of STPA to an experimental radiotherapy facility and, through this feasibility check, potentially influenced the state of the art in hazard analysis of medical devices and health care delivery; - Advanced the STPA methodology by creating notations and a process to document, query and visualize the possibly large number of hazardous scenarios identified by STPA analyses, with the goal of facilitating their review and use by their intended audience; Showed how STPA is complementary to more traditional hazard analysis techniques such as fault and event trees. Their respective strengths can be summoned when STPA is used to identify areas on which to focus the investigation lens of traditional hazard analysis techniques. Keywords: STAMP, STPA, hazard analysis, risk analysis, risk management, proton therapy, medical devices, safety, certificationby Blandine Antoine.Ph.D

    New technology for NATO: implementing Follow-On Forces Attack

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    The report briefly reviews what Follow-On Forces Attack (FOFA) is and how it fits into NATO strategy, but is primarily concerned with the outstanding technical issues, how our Allies view FOFA, how the Soviets might respond to it, and how the various technical developments might be brought together into “packages” of systems to support specific operational concepts
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