47 research outputs found

    The CUAVA-2 CubeSat: A Second Attempt to Fly the Remote Sensing, Space Weather Study and Earth Observation Instruments

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    This paper presents the 6U CubeSat mission conducted by the ARC Training Centre for CubeSats, UAVs, and their Applications (CUAVA) at the University of Sydney. CUAVA-2, the second CubeSat project following the CUAVA-1 mission, builds upon lessons learned from its predecessor. CUAVA-1, the first satellite launched by CUAVA, carried first-generation payloads for earth observation goals and technology demonstrations but experienced communication difficulties. A fault root analysis was performed on CUAVA-1 to inform the design of CUAVA-2. The CUAVA-2 satellite incorporates a hyperspectral imager for applications in agriculture, forestry, coastal and marine environments, urban areas, water hazard assessment, and mineral exploration. It also includes a GPS reflectometry payload for remote sea state determination, as well as secondary payloads for technology demonstration and space weather study. This paper discusses the fault analysis findings, lessons learned, and design inputs from CUAVA-1, showcasing their integration into the CUAVA-2 satellite, which is scheduled for launch in February 2024

    LDRD project final report : hybrid AI/cognitive tactical behavior framework for LVC.

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    This Lab-Directed Research and Development (LDRD) sought to develop technology that enhances scenario construction speed, entity behavior robustness, and scalability in Live-Virtual-Constructive (LVC) simulation. We investigated issues in both simulation architecture and behavior modeling. We developed path-planning technology that improves the ability to express intent in the planning task while still permitting an efficient search algorithm. An LVC simulation demonstrated how this enables 'one-click' layout of squad tactical paths, as well as dynamic re-planning for simulated squads and for real and simulated mobile robots. We identified human response latencies that can be exploited in parallel/distributed architectures. We did an experimental study to determine where parallelization would be productive in Umbra-based force-on-force (FOF) simulations. We developed and implemented a data-driven simulation composition approach that solves entity class hierarchy issues and supports assurance of simulation fairness. Finally, we proposed a flexible framework to enable integration of multiple behavior modeling components that model working memory phenomena with different degrees of sophistication

    Estimation and simulation of foraging trips in land-based marine predators

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    The behavior of colony-based marine predators is the focus of much research globally. Large telemetry and tracking data sets have been collected for this group of animals, and are accompanied by many empirical studies that seek to segment tracks in some useful way, as well as theoretical studies of optimal foraging strategies. However, relatively few studies have detailed statistical methods for inferring behaviors in central place foraging trips. In this paper we describe an approach based on hidden Markov models, which splits foraging trips into segments labeled as “outbound”, “search”, “forage”, and “inbound”. By structuring the hidden Markov model transition matrix appropriately, the model naturally handles the sequence of behaviors within a foraging trip. Additionally, by structuring the model in this way, we are able to develop realistic simulations from the fitted model. We demonstrate our approach on data from southern elephant seals (Mirounga leonina) tagged on Kerguelen Island in the Southern Ocean. We discuss the differences between our 4-state model and the widely used 2-state model, and the advantages and disadvantages of employing a more complex model

    The CUAVA-1 CubeSat—A Pathfinder Satellite for Remote Sensing and Earth Observation

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    In this paper we report a 3U CubeSat named CUAVA-1 designed by the ARC Training Centre for CubeSats, UAVs, and Their Applications (CUAVA). CUAVA, funded by the Australian Research Council, aims to train students, develop new instruments and technology to solve crucial problems, and help develop a world-class Australian industry in CubeSats, UAVs, and related products. The CUAVA-1 project is the Centre’s first CubeSat mission, following on from the 2 Australian satellites INSPIRE-2 and UNSW-EC0 CubeSats that launched in 2017. The mission is designed to serve as a precursor for a series of Earth observations missions and to demonstrate new technologies developed by our partners. We also intend to use the satellite to provide students hands-on experiences and to gain experience for our engineering, science and industry teams for future, more complex, missions

    Outstanding challenges in the transferability of ecological models

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    Predictive models are central to many scientific disciplines and vital for informing management in a rapidly changing world. However, limited understanding of the accuracy and precision of models transferred to novel conditions (their ‘transferability’) undermines confidence in their predictions. Here, 50 experts identified priority knowledge gaps which, if filled, will most improve model transfers. These are summarized into six technical and six fundamental challenges, which underlie the combined need to intensify research on the determinants of ecological predictability, including species traits and data quality, and develop best practices for transferring models. Of high importance is the identification of a widely applicable set of transferability metrics, with appropriate tools to quantify the sources and impacts of prediction uncertainty under novel conditions

    The OpenMolcas Web: A Community-Driven Approach to Advancing Computational Chemistry

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    The developments of the open-source OpenMolcas chemistry software environment since spring 2020 are described, with a focus on novel functionalities accessible in the stable branch of the package or via interfaces with other packages. These developments span a wide range of topics in computational chemistry and are presented in thematic sections: electronic structure theory, electronic spectroscopy simulations, analytic gradients and molecular structure optimizations, ab initio molecular dynamics, and other new features. This report offers an overview of the chemical phenomena and processes OpenMolcas can address, while showing that OpenMolcas is an attractive platform for state-of-the-art atomistic computer simulations

    Global assessment of marine plastic exposure risk for oceanic birds

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    Plastic pollution is distributed patchily around the world’s oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species. Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species

    Global assessment of marine plastic exposure risk for oceanic birds

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    Plastic pollution is distributed patchily around the world's oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species. Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species.B.L.C., C.H., and A.M. were funded by the Cambridge Conservation Initiative’s Collaborative Fund sponsored by the Prince Albert II of Monaco Foundation. E.J.P. was supported by the Natural Environment Research Council C-CLEAR doctoral training programme (Grant no. NE/S007164/1). We are grateful to all those who assisted with the collection and curation of tracking data. Further details are provided in the Supplementary Acknowledgements. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Peer reviewe

    Global assessment of marine plastic exposure risk for oceanic birds

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    Plastic pollution is distributed patchily around the world’s oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species. Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species

    Radio Emissions from Earth’s Foreshock and Bolides

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    It is well understood that Earth’s foreshock radiation is due to the bow shock deflecting the solar wind and accelerating electrons upstream into the foreshock where they produce Langmuir waves and radio emissions. Recently, the Long Wavelength Array (LWA) in the USA observed radio waves from meteors and other bolides entering the ionosphere and atmosphere. Here we correct and generalise the model for Earth’s foreshock radiation by Kuncic et al. (2004) and adapt it to the bolide case. We also produce the first 2D source pictures of Earth’s foreshock radiation, confirming the prediction from Gurnett et al. (1993) that the radio source should be elongated perpendicular to the plane containing the magnetic field vector. For the bolide case, we show that our predicted fluxes are in the same range as observations by Obenberger and Taylor (2018) and therefore the theory is now a viable explanation for radio emissions from fireballs. Jordens förströmsstrĂ„lning beror pĂ„ att bĂ„gchocken avböjer solvinden och accelererar elektroner uppströms in i förskotten dĂ€r de producerar Langmuir- vĂ„gor och radioutslĂ€pp. Nyligen observerade Long Wavelength Array (LWA) i USA radiovĂ„gor frĂ„n meteorer och andra bolider som kom in i jonosfĂ€ren och atmosfĂ€ren. HĂ€r korrigerar och generaliserar vi modellen för jordens förströmsstrĂ„lning av Kuncic et al. (2004) och anpassar den till bolide- fallet. Vi producerar ocksĂ„ de första 2DkĂ€llbilderna av jordens förströmsstrĂ„lning, vilket bekrĂ€ftar förutsĂ€gelsen frĂ„n Gurnett et al. (1993): att radiokĂ€llan skulle vara utstrĂ€ckt vinkelrĂ€tt mot planet som innehĂ„ller magnetfĂ€ltvektorn. För bolide- fallet visar vi att vĂ„ra förutspĂ„dda flöden ligger inom samma intervall som observationer frĂ„n Obenberger och Taylor (2018), dĂ€rav Ă€r teorin nu en gĂ„ngbar förklaring till radioutslĂ€pp frĂ„n större meteorer
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