Analyzing high resolution topography for advancing the understanding of mass and energy transfer through landscapes: A review

International audienceThe study of mass and energy transfer across landscapes has recently evolved to comprehensive considerations acknowledging the role of biota and humans as geomorphic agents, as well as the importance of small-scale landscape features. A contributing and supporting factor to this evolution is the emergence over the last two decades of technologies able to acquire high resolution topography (HRT) (meter and sub-meter resolution) data. Landscape features can now be captured at an appropriately fine spatial resolution at which surface processes operate; this has revolutionized the way we study Earth-surface processes. The wealth of information contained in HRT also presents considerable challenges. For example, selection of the most appropriate type of HRT data for a given application is not trivial. No definitive approach exists for identifying and filtering erroneous or unwanted data, yet inappropriate filtering can create artifacts or eliminate/distort critical features. Estimates of errors and uncertainty are often poorly defined and typically fail to represent the spatial heterogeneity of the dataset, which may introduce bias or error for many analyses. For ease of use, gridded products are typically preferred rather than the more information-rich point cloud representations. Thus many users take advantage of only a fraction of the available data, which has furthermore been subjected to a series of operations often not known or investigated by the user. Lastly, standard HRT analysis work-flows are yet to be established for many popular HRT operations, which has contributed to the limited use of point cloud data.In this review, we identify key research questions relevant to the Earth-surface processes community within the theme of mass and energy transfer across landscapes and offer guidance on how to identify the most appropriate topographic data type for the analysis of interest. We describe the operations commonly performed from raw data to raster products and we identify key considerations and suggest appropriate work-flows for each, pointing to useful resources and available tools. Future research directions should stimulate further development of tools that take advantage of the wealth of information contained in the HRT data and address the present and upcoming research needs such as the ability to filter out unwanted data, compute spatially variable estimates of uncertainty and perform multi-scale analyses. While we focus primarily on HRT applications for mass and energy transfer, we envision this review to be relevant beyond the Earth-surface processes community for a much broader range of applications involving the analysis of HRT

Bathymetric Survey of the St. Anthony Channel (Croatia) Using Multibeam Echosounders (MBES)—A New Methodological Semi-Automatic Approach of Point Cloud Post-Processing

Multibeam echosounders (MBES) have become a valuable tool for underwater floor mapping. However, MBES data are often loaded with different measurement errors. This study presents a new user-friendly and methodological semi-automatic approach of point cloud post-processing error removal. The St. Anthony Channel (Croatia) was selected as the research area because it is regarded as one of the most demanding sea or river passages in the world and it is protected as a significant landscape by the Šibenik-Knin County. The two main objectives of this study, conducted within the Interreg Italy–Croatia PEPSEA project, were to: (a) propose a methodological framework that would enable the easier and user-friendly identification and removal of the errors in MBES data; (b) create a high-resolution integral model (MBES and UAV data) of the St. Anthony Channel for maritime safety and tourism promotion purposes. A hydrographic survey of the channel was carried out using WASSP S3 MBES while UAV photogrammetry was performed using Matrice 210 RTK V2. The proposed semi-automatic post-processing of the MBES acquired point cloud was completed in the Open Source CloudCompare software following five steps in which various point filtering methods were used. The reduction percentage in points after the denoising process was 14.11%. Our results provided: (a) a new user-friendly methodological framework for MBES point filtering; (b) a detailed bathymetric map of the St. Anthony Channel with a spatial resolution of 50 cm; and (c) the first integral (MBES and UAV) high-resolution model of the St. Anthony Channel. The generated models can primarily be used for maritime safety and tourism promotion purposes. In future research, ground-truthing methods (e.g., ROVs) will be used to validate the generated models

Conceptual design of a fleet of autonomous regolith throwing devices for radiation shielding of lunar habitats

The National Aeronautics and Space Administration (NASA) in conjunction with Universities Space Research Association (USRA) has requested that the feasibility of a fleet of regolith tossing devices designed to cover a lunar habitat for radiation protection be demonstrated. The regolith, or lunar soil, protects the lunar habitat and its inhabitants from radiation. Ideally, the device will operate autonomously in the lunar environment. To prove the feasibility of throwing regolith on the Moon, throwing solutions were compared to traditional, Earth-based methods for moving soil. Various throwing configurations were investigated. A linear throwing motion combined with a spring and motor energizing system proved a superior solution. Three different overall configurations for the lunar device are presented. A single configuration is chosen and critical parameters such as operating procedure, system volume, mass, and power are developed. The report is divided into seven main sections. First, the Introduction section gives background information, defines the project requirements and the design criteria, and presents the methodology used for the completion of this design. Next, the Preliminary Analysis section presents background information on characteristics of lunar habitats and the lunar environment. Then, the Alternate Designs section presents alternate solutions to each of the critical functions of the device. Fourth, a detailed analysis of throwing the regolith is done to demonstrate its feasibility. Then, the three overall design configurations are presented. Next, a configuration is selected and the conceptual design is expanded to include system performance characteristics, size, and mass. Finally, the Conclusions and Recommendations for Future Work section evaluates the design, outlines the next step to be taken in the design process, and suggests possible goals for future design work

Soundings: the Newsletter of the Monterey Bay Chapter of the American Cetacean Society. 2004

(PDF contains 92 pages.

Distribution-free, Variable Resolution Depth Estimation with Composite Uncertainty

Recent algorithms for processing hydrographic data have treated the problem of achievable resolution by constructing grids of fixed resolution, a composite grid of variable resolution, recursive sub-division in a quad-tree, or by relying on a comprehensive TIN of the original points. These algorithms all impose some artificial structure on the data to allow for efficient computation, however, which this paper attempts to address. A scheme is outlined which provides a robust estimate of depth and associated uncertainty that makes as few assumptions as possible. Using a non-uniform spectral analysis, it estimates the spatial scales at which the data are consistent so it can estimate within the Nyquist limit for the underlying surface. Kernel density techniques estimate the most likely depth, and density partitioning estimates the observational and modeling uncertainty. After correcting for potential biases the uncertainty is augmented using a modified Hare-Godin-Mayer system integration uncertainty and a sound speed profile variability due to Beaudoin et al. The result is a robust, distributionfree, continuously variable-resolution estimate of depth with an associated uncertainty. This algorithm is illustrated by estimating the depth (and uncertainty) of Challenger Deep, and the paper then provides some perspectives on efficiency, extensibility and adaptability of this algorithm in the hydrographic context

Modelado del último de los “Movies”: discusión y levantamiento digital del Eothen anteriormente conocido como ML286

[EN] The research presented here puts together different direct and/or physical operations all aimed to enhance the knowledge and produce advanced dissemination of the very last ship from the “Mosquitos’ Fleet” which operated during the World War I and in some operations even during the World War II. The exploration of the valuable remains along the Thames River in London, the intervention with archaeology strategy, the use of digital survey procedures, the investigation of the references about the fleet, the digital modelling and drawing and the final online sharing of the 3D model, brought together to a specific digital heritage creation of an element with a high risk of getting lost. An international team worked together on the poor shipwreck of the Eothen (the last name assigned to this ship by its last owner). The intervention was operated in very odd operative conditions, with the hull invaded by the mud, the very wet environment and the daily flood of the area, such a mix of difficult conditions were a special challenge for the survey operations, which were optimized and accurately planned to allow the best and efficient result in terms of coverage and level of details. The following post-processing aimed to the production of a classic set of 2D drawings and an interactive 3D model, accessible in a real-time visualization from the sketchfab.com platform creates an excellent base for a possible following restoration/musealisation intervention, or, at least, allow digital preservation of a rich dataset of the remains of this interesting piece from the naval history of the first half of the 20th century.[ES] La investigación que aquí se muestra reúne diferentes operaciones directas y/o físicas, todas orientadas a mejorar el conocimiento y producir una puesta en valor del último barco de la “Flota de Mosquitos” que operó durante la Primera Guerra Mundial y en algunas operaciones incluso durante la Segunda Guerra Mundial. Presentamos la exploración de los valiosos restos a lo largo del río Támesis en Londres, la intervención con estrategia arqueológica, el uso de procedimientos de levantamiento digital, la investigación de las referencias sobre la embarcación, el modelado y dibujo digital, y el intercambio final en línea del modelo 3D, reunidos en una aportación de patrimonio digital específico de un elemento con alto riesgo de perderse. Un equipo internacional , trabajaron juntos en el naufragio del Eothen (nombre asignado a este barco por su último propietario). La toma de datos se realizó en condiciones operativas muy complejas, con el casco invadido por el limo del rio, el entorno muy húmedo y la inundación diaria de la zona; esta mezcla de condiciones difíciles fueron un desafío especial para llevar a cabo las operaciones de levantamiento, las cuales fueron optimizadas con el objetivo de obtener el mejor y más eficiente resultado en términos de cobertura y nivel de detalle. El siguiente posprocesamiento estuvo dirigido a la obtención de un conjunto clásico de dibujos 2D, así como de un modelo 3D interactivo, accesible en una visualización en tiempo real desde la plataforma Sketchfab.com. Así se ha creado una base excelente para una posible intervención posterior de restauración/musealización, o, al menos, para obtener la preservación digital de un rico conjunto de datos de los restos de esta interesante pieza de la historia naval, de la primera mitad del siglo XX.Rodríguez-Navarro, P.; Wragg, E.; Verdiani, G.; Gil-Piqueras, T. (2021). Modelling the last of the “Movies”: discussion and digital survey of the Eothen formerly ML286. Virtual Archaeology Review. 12(25):57-72. https://doi.org/10.4995/var.2021.1454357721225Adm. 337/121/565. Admiralty: Royal Naval Volunteer Reserve: Records of Service, First World War. The National Archives, Kew, UK.Aspinall- Oglander, C. (1951). Roger Keyes. London: Hogarth.Association of Dunkirk Little Ships. Webpage accessed September 18, 2018, from http://www.adls.org.uk/t1/node/583.Brown, M. & Meehan, P. (2002). Scapa Flow. London: Pan Books.Cam2 Faro Technologies (2017). Faro Laser Scanner User Manual, online version, Faro Product Info, available from http://www.faro.com (last accessed August 2018).Compton- Hall, R. (2004). Submarines at War 1939-45. Penzance: Periscope.Corbett, J. (1938). History of the Great War. Naval Operations, Vol. 1. London: Longmans Green and Co.English, J. (2004). Auxiliary Warships. In D. Brown (Ed.), The Eclipse of the Big Gun. London, England: Conway Maritime Press.Evans, A., Romeo, M., Bahrehmand, A., Agenjo, J., & Blat, J. (2014). 3D graphics on the web: A survey. Computers & Graphics, 41, 43-61. https://doi.org/10.1016/j.cag.2014.02.002Firth, A. (2014). East Coast War Channels in the First and Second World War. Unpublished report for English Heritage. EH Project Number 6586, Fjordr Ref: 16131. Tisbury: Fjordr Limited.Firth, A. (2015a). East Coast War Channels: a landscape approach to battlefield archaeology in the North Sea. International Journal of Nautical Archaeology, 44(2), 438-445. https://doi.org/10.1111/1095-9270.12113Firth, A. (2015b). The East Coast War Channels in the First World War: rediscovering a lost battlefield in the North Sea. Historic England Research, 1, 3-7.Fisher, S. (2018). Building the Motor Launch armada. Unpublished document, Ronin Archaeology.Friedman, N. (2004). The Aircraft Carrier. In D. Brown (Ed.), The Eclipse of the Big Bun. London, England: Conway Maritime Press.Gordon, A. (2005). The Rules of the game. Jutland and British naval command. London, England: John Murray.Guarnieri, A., Pirotti, F. & Vettore, A. (2010). Cultural heritage interactive 3D models on the web: An approach using open source and free software. Journal of Cultural Heritage, 11(3), 350-353. https://doi.org/10.1016/j.culher.2009.11.011Grussenmeyer, P., Landes, T., Doneus, M., & Lerma, J. L. (2016). Basics of range-based modelling techniques in Cultural Heritage. In E. Stylianidis, F. Remondino (Eds.), 3D Recording, Documentation and Management of Cultural Heritage (Chapter 6, pp. 305-368). Dunbeath, Scotland: Whittles Publishing.Guidi, G., Micoli, L. L., Gonizzi, S., Brennan, M. & B. Frischer. (2015). Image-based 3D capture of cultural heritage artifacts an experimental study about 3D data quality. 2015 Digital Heritage (pp. 321-324). Granada, Spain: IEEE. https://doi.org/10.1109/DigitalHeritage.2015.7419514Kwan, Y. (2016). Laser Scanning, Theory and Applications. USA: Scitus Academics LLC.Lambert, A. (2008). Admirals. London: Faber and Faber.Management Association, I. (Ed.). (2018). Gamification in Education: Breakthroughs in Research and Practice. USA: IGI Global. https://doi.org/10.4018/978-1-5225-5198-0Maxwell, G. S. (1920). The Motor Launch Patrol. London and Toronto: J.M. Dent and sons.Morris, J. (1995). Fisher's Face. London, England: Penguin.Motor Launch Patrol. Webpage accessed November 21, 2018:http://motorlaunchpatrol.net/history/post_war/rhine_patrol_flotilla/rhine_patrol_flotilla-2.phphttp://motorlaunchpatrol.net/history/post_war/rhine_patrol_flotilla/http://motorlaunchpatrol.net/history/post_war/http://motorlaunchpatrol.net/history/post_war/irish_free_state/http://motorlaunchpatrol.net/history/post_war/the_forgotten_flagship/http://motorlaunchpatrol.net/history/pleasure_yacht/Omura, G. & Benton, B. C. (2018). Mastering AutoCAD 2019 and AutoCAD LT 2019. USA: John Wiley & Sons. https://doi.org/10.1002/9781119495048Rojas-Sola, J. I., de la Morena-de la Fuente, E. (2018). Digital 3D reconstruction of Betancourt's historical heritage: the dredging machine in the Port of Kronstadt. Virtual Archaeology Review, 9(18), 44-56. https://doi.org/10.4995/var.2018.7946Ross, A. (2004). Costal Forces. In D. Brown (Ed.), The Eclipse of the Big Bun. London, England: Conway Maritime Press.Shan, J. & Toth, C. K. (2017). Topographic Laser Ranging and Scanning: Principles and Processing. USA: CRC Press. https://doi.org/10.1201/9781420051438Spitfires of the Sea. Webpage accessed November 25, 2018: https://spitfiresofthesea.com/industrial-might/.Sutphen, H. R. (1920). The building of the ships. In G. S. Maxwell (Ed.), The Motor Launch Patrol. London and Toronto: J. M. Dent and sons.Terraine, J. (1999). Business in Great Waters. Ware, England: Wordsworth Editions Ltd.West, S. (2017). Geoffrey Alfree 1889-1918. In N. Cohen, & E. Wragg, The River's Tale: The Archaeology of the Thames Foreshore in Greater London. London, England: Museum of London Archaeology

Echoes in motion: An acoustic camera (DIDSON) as a monitoring tool in applied freshwater ecology

Aquatic environments are increasingly faced with anthropogenic impact. Rivers have been fully developed into navigable waterways resulting in a dramatic loss of habitats and longitudinal and horizontal disconnection. Human sewage polluted rivers and in addition with overfishing and a rising recreational use, most European diadromous fish species have suffered and can be graded as vulnerable. Species-conservation and re-stocking projects support to save diverse fish communities. Capable monitoring- and assessment tools are urgent, given that knowledge is the key for sustainable management. The DIDSON, a multibeam sonar, delivers video-like live images in high resolution, enabling the measurement of fish length and behavioral observations even in turbid water and by night in a non-invasive manner. It could be shown that a special application of the sonar offers potential to discriminate fish species based on their characteristic acoustic shadows. Beside the possibility to count and measure fish and to observe their behavior this provides additional valuable information in certain monitoring applications. New insights in the spawning behavior of Alosa Alosa could be revealed on a spawning site in the Garonne River, France. It could be observed that spawning events are not restricted to one couple since additional individuals join. Drifting clouds of sexual products and micro bubbles could be detected with the sonar and were consistent with the number of sound based spawning measurements (by human hearing) and thus served as an indicator for spawning activity. A mid- term application of the sonar in front of a trash rack of a hydro power plant demonstrated the potential to gain knowledge in the field of spatial ecology of fish with high temporal resolution. An hourly fish abundance raster was chosen as a measure of fish activity to intuitively illustrate alternating diel and seasonal activity patterns at a glance. Distinct patterns and migration peaks of three groups ‘fish’, ‘eels’ and ‘shoals’ could be identified. The size class potentially at risk to pass the trash rack, was faced the power production data to identify time windows of higher and lower risk of entrainment and respective fish protection requirements