44 research outputs found
Security event recognition for visual surveillance
With rapidly increasing deployment of surveillance cameras, the reliable methods for automatically analyzing the surveillance video and recognizing special events are demanded by different practical applications. This paper proposes a novel effective framework for security event analysis in surveillance videos. First, convolutional neural network (CNN) framework is used to detect objects of interest in the given videos. Second, the owners of the objects are recognized and monitored in real-time as well. If anyone moves any object, this person will be verified whether he/she is its owner. If not, this event will be further analyzed and distinguished between two different scenes: moving the object away or stealing it. To validate the proposed approach, a new video dataset consisting of various scenarios is constructed for more complex tasks. For comparison purpose, the experiments are also carried out on the benchmark databases related to the task on abandoned luggage detection. The experimental results show that the proposed approach outperforms the state-of-the-art methods and effective in recognizing complex security events. © 2017 Copernicus GmbH. All rights reserved
SEARCHING LOST PEOPLE WITH UAVS: THE SYSTEM AND RESULTS OF THE CLOSE-SEARCH PROJECT
This paper will introduce the goals, concept and results of the project named CLOSE-SEARCH, which stands for âAccurate and safe EGNOS-SoL Navigation for UAV-based low-cost Search-And-Rescue (SAR) operationsâ. The main goal is to integrate a medium-size, helicopter-type Unmanned Aerial Vehicle (UAV), a thermal imaging sensor and an EGNOS-based multi-sensor navigation system, including an Autonomous Integrity Monitoring (AIM) capability, to support search operations in difficult-to-access areas and/or night operations. The focus of the paper is three-fold. Firstly, the operational and technical challenges of the proposed approach are discussed, such as ultra-safe multi-sensor navigation system, the use of combined thermal and optical vision (infrared plus visible) for person recognition and Beyond-Line-Of-Sight communications among others. Secondly, the implementation of the integrity concept for UAV platforms is discussed herein through the AIM approach. Based on the potential of the geodetic quality analysis and on the use of the European EGNOS system as a navigation performance starting point, AIM approaches integrity from the precision standpoint; that is, the derivation of Horizontal and Vertical Protection Levels (HPLs, VPLs) from a realistic precision estimation of the position parameters is performed and compared to predefined Alert Limits (ALs). Finally, some results from the project test campaigns are described to report on particular project achievements. Together with actual Search-and-Rescue teams, the system was operated in realistic, user-chosen test scenarios. In this context, and specially focusing on the EGNOS-based UAV navigation, the AIM capability and also the RGB/thermal imaging subsystem, a summary of the 1 INTRODUCTION The use of Unmanned Aerial Vehicles (UAVs) âmore in gen- eral, Unmanned Aerial Systems (UASs)â for SAR operations is not new and has been traditionally fed by developments made in other fields. The main driver of UAV technology has been (and still is) the military field and this is because the nature of military developments is fairly overlapping SAR needs. As a example of that, we recall the UAVs used in the Iraq and Afghanistan wars were deployed to find people trapped in New Orleans buildings devastated by Hurricane Katrinas flood waters. Those platforms were equipped with thermal imaging systems to detect the body heat of storm survivors. A second example was the use of rotary- wing UAV platforms providing on-site imagery from the nuclear incident in Fukushima. More recently, a field that is increasingly putting effort on UAV development is Geomatics: the potential of those light-weight, easy-deployable platforms to quickly provide aerial and/or ground, good quality imagery is huge. A clear ex- ample of this interest raised within the geomatic community is the recent acquisition of Gateway, a provider of lightweight UAVs for photogrammetry and rapid terrain mapping applications, by Trimble. Indeed, the multi-application of the UAV potential to other fields, such as SAR, shall not be neglected. And even if [the lack of] regulations have been the stopper of the final jump to commercial applications, the willingness of regulators seems finally positive on pulling the trigger. As stated in the Institute of Navigation newsletter in winter 2011, âthe United States trans- portation secretary must develop a comprehensive plan to safely accelerate the integration of civil UAS into the national airspace system as soon as practicable, but not later than September 30th, 2015.â results is presented
Geometric Calibration and Radiometric Correction of LiDAR Data and Their Impact on the Quality of Derived Products
LiDAR (Light Detection And Ranging) systems are capable of providing 3D positional and spectral information (in the utilized spectrum range) of the mapped surface. Due to systematic errors in the system parameters and measurements, LiDAR systems require geometric calibration and radiometric correction of the intensity data in order to maximize the benefit from the collected positional and spectral information. This paper presents a practical approach for the geometric calibration of LiDAR systems and radiometric correction of collected intensity data while investigating their impact on the quality of the derived products. The proposed approach includes the use of a quasi-rigorous geometric calibration and the radar equation for the radiometric correction of intensity data. The proposed quasi-rigorous calibration procedure requires time-tagged point cloud and trajectory position data, which are available to most of the data users. The paper presents a methodology for evaluating the impact of the geometric calibration on the relative and absolute accuracy of the LiDAR point cloud. Furthermore, the impact of the geometric calibration and radiometric correction on land cover classification accuracy is investigated. The feasibility of the proposed methods and their impact on the derived products are demonstrated through experimental results using real data
PHOTOGRAMMETRIC MISSION PLANNER FOR RPAS
This paper presents a development of an open-source flight planning tool for Remotely Piloted Aircraft Systems (RPAS) that is dedicated to high-precision photogrammetric mapping. This tool contains planning functions that are usually available in professional mapping systems for manned aircrafts as well as new features related to GPS signal masking in complex (e.g. mountainous) terrain. The application is based on the open-source Java SDK (Software Development Kit) World Wind from NASA that contains the main geospatial components facilitating the development itself. Besides standard planning functions known from other mission planners, we mainly focus on additional features dealing with safety and accuracy, such as GPS quality assessment. The need for the development came as a response for unifying mission planning across different platforms (e.g. rotary or fixed wing) operating over terrain of different complexity. A special attention is given to the user interface, that is intuitive to use and cost-effective with respect to computer resources
DNA cloning demonstrates high genetic heterogeneity in populations of the subaerial green alga Trentepohlia (Trentepohliales, Chlorophyta)
Mats of the green alga Trentepohlia, a genus widely distributed in the tropics as well as temperate regions,
have always been perceived as homogeneous (i.e., formed by only one species). As such, their general
nature and specific feature play a supportive role in the species delimitation. However, the presence of
morphologically dissimilar thalli was observed under the light microscope and when cultivating a piece of a
single mat. To address this, we performed DNA cloning of the rbcL gene on mat fragments of T. abietina, T. annulata, T. jolithus and T. umbrina sampled in Europe to reveal if they are composed of one or more species. We revealed that more Trentepohlia haplotypes may coexist in a single mat. In consideration of this, we conclude that the use of material isolated in unialgal culture will be almost mandatory for a taxonomic reassessment of this complicated genus. Another direct implication of this problem is that herbarium specimens consisting of field-collected material should not be used for direct sequencing. We further hypothesize the reasons why multiple haplotypes of Trentepohlia occur more frequently in the tuft-like mats. Possibly, fragments and/or cells of other microalgae, including other species of Trentepohlia, might be retained in such mats more easily than in the crustose trentepohlialean mats
2004): Photogrammetry-Derived Navigation Parameters for INS Kalman Filter Updates
In this paper, a GPS-independent mobile navigation and mapping system is introduced. This system employs the photogrammetric intersection to determine the coordinates of the surrounding objects and then it uses these newly known objects to compute its own position, when it moves, by the photogrammetric resection. The photogrammetric resection output â the exterior orientation parameters â is then used as external measurements in an INS Kalman Filer to compute the filtered exterior orientation parameters to do the intersection. This methodology of navigation and mapping is applied in the robotics community using different sensors and methods, where it is called Simultaneous Localisation And Mapping (SLAM); SLAM is the problem of mapping an area and at the same time using the map to locate the robot. In this paper, the solution for SLAM by integrating photogrammetry resection output and INS via a Kalman Filer is described. 1
Interaction between Local Plate Buckling and Overall Buckling in Thin-Walled Compression Members â Theories and Experiments
Autarktic and inertial measurement based low-cost reconstruction of motorcycle forward speed
Ecological differentiation of cryptic species in green microalgae
Abstract - 65th Meeting of the Phycological Society of Americ