scholarly journals SIMULTANEOUS DATA SYSTEM FOR INSTRUMENTING THE SHELF

1972 ◽  
Vol 1 (13) ◽  
pp. 2 ◽  
Author(s):  
Robert L. Lowe ◽  
Douglas L. Inman ◽  
Richard M. Brush
Keyword(s):  
Surf Zone ◽  
Continuous Wave ◽  
Dynamic Environment ◽  
Time Correlation ◽  
Wave Climate ◽  
Real Time System ◽  
Shore Station ◽  
Shelf Station ◽  
Wave Sensors ◽  
Rapid Deployment

A system, designed to give maximum flexibility and portability, has been developed to collect wave, current and other physical data within the dynamic environment from the surf zone to the edge of the shelf. The system consists of a radio-linked shore station, housed in a mobile van and as many as six shelf stations mounted in bottom referencing spars. A shelf station can be deployed from a small boat with minimum diver time. The ease of deployment of the shelf stations coupled with the mobile self-contained shore station, allows the use of a modern data acquisition system, and rapid deployment of sensors, for the field study of remote coastal areas. Each of the shelf stations is designed to accomodate as many as fifteen sensors. All simultaneous sensor outputs are digitized and transmitted by radio to the mobile shore station, where the received signals are processed and selected for recording on strip charts or digital magnetic tapes for computer analyses. Very high sampling rates and a real time system are used to insure precise time correlation between all data channels including those from separate shelf stations. A single shelf station would transmit data from an array of wave sensors, thus providing continuous wave climate including the two dimensional wave spectra. Some different combinations of shelf station ensembles are shown.

Morphodynamic forecast uncertainty due to bathymetry unknowns

2021 ◽  
Author(s):  
Xavier Sánchez-Artús ◽  
Vicente Gracia ◽  
Manuel Espino Infantes ◽  
Agustín Sánchez-Arcilla Conejo
Keyword(s):  
Surf Zone ◽  
Energy Content ◽  
Numerical Models ◽  
Morphological Evolution ◽  
Morphological Response ◽  
Statistical Characterization ◽  
Morphodynamic Modelling ◽  
Coastal Risks ◽  
Rapid Deployment ◽  
Bathymetric Changes

<p>Operational morphodynamic modelling is becoming an attractive tool for managers to forecast and reduce coastal risks. The development of highly sophisticated numerical models during the last decades has underpinned the simulation of beach morphological evolution due to wave impacts. However, there are still some fundamental aspects, such as the bathymetric uncertainty, that needs to be regularly updated in the modelling chain to avoid a worthless forecast. It is also very well known that the surf zone is the most highly dynamic area although the bathymetry changes between certain limits. In this work, we explore the influence of bathymetric changes in morphodynamic forecasts. XBEACH is used to model the morphological response of a dissipative urban low-lying sandy coastal stretch (Barcelona, Spain) for different forecasted storms to determine the uncertainty bands of predicted coastal erosion and flooding. We consider as benchmarks the results of XBEACH simulations fed with the bathymetric information taken from existing nautical charts. An analysis of the possible beach states of the studied area following the Wright and Short (1984) is later performed to determine a range of topo-bathymetric configurations that will be used to run the model again. These new simulations are used to determine the uncertainty of the erosion and flooding results. The energy content of the storm in terms of intensity and duration uncertainty is also considered in the analysis. The proposed ensemble approach will serve to determine the likelihood of the modelling forecast outputs. Such statistical characterization is aligned with ensemble forecasting in meteo-oceanographic fields and will provide robust information for coastal decision making, for instance when considering proactive rapid deployment measures against a forecasted storm.</p>

scholarly journals Sediment Transport Beyond the Surf Zone Under Waves and Currents of the Non-Tidal Sea: Lubiatowo (Poland) Case Study

2016 ◽  
Vol 63 (1) ◽  
pp. 63-77 ◽  
Author(s):  
Rafał Ostrowski ◽  
Magdalena Stella
Keyword(s):  
Sediment Transport ◽  
Surf Zone ◽  
Coastal Region ◽  
Wave Climate ◽  
Soil Parameters ◽  
Shear Stresses ◽  
Research Station ◽  
Sea Bed ◽  
Waves And Currents ◽  
Bed Changes

Abstract The paper deals with the sandy coastal zone at Lubiatowo in Poland (the south Baltic Sea). The study comprises experimental and theoretical investigations of hydrodynamic and lithodynamic processes in the coastal region located close to the seaward boundary of the surf zone and beyond the surf zone. The analysis is based on field data collected at the IBW PAN Coastal Research Station in Lubiatowo. The data consist of wind velocity reconstructed from the long-term wave climate, deep-water wave buoy records and sea bottom soil parameters. Nearbed flow velocities induced by waves and currents, as well as bed shear stresses are theoretically modelled for various conditions to determine sediment motion regimes in the considered area. The paper discusses the possibility of occasional intensive sediment transport and the occurrence of distinct sea bed changes at bigger water depths.

scholarly journals Ant Based Zonal Routing in Mobile Adhoc Networks

2018 ◽  
Vol 7 (3.1) ◽  
pp. 46
Author(s):  
Gurpreet Singh ◽  
Amanpreet Kaur ◽  
Aashdeep Singh ◽  
Rohan Gupta
Keyword(s):  
Ad Hoc Network ◽  
Ad Hoc ◽  
Mobile Ad Hoc Network ◽  
Dynamic Environment ◽  
Node Mobility ◽  
Frequent Change ◽  
Mobile Ad Hoc ◽  
Rapid Deployment ◽  
Asymmetric Links ◽  
Core Issues

Mobile Ad hoc network (MANET) is a collection of moving wireless nodes which form a temporary network topology without using any pre-existing network infrastructure. One of the challenges in MANET is to identify a path between the source and the destination nodes. MANET is highly deployable, self-organizing, autonomous and self-configuring network with the ability of rapid deployment. Nodes movement imposes high challenges to routing in MANET due to dynamically changing of topologies, low transmission power and asymmetric links. So well-organized routing is very critical task due to highly dynamic environment. Route instability occurs due to node mobility and leads to frequent change in topologies; therefore routing becomes one of the core issues. Many researchers are working on the expansion of routing protocols in MANET. 

scholarly journals A LONG-TERM EQUILIBRIUM BEACH PLANFORM MODEL FOR COASTAL WORK DESIGN

2012 ◽  
Vol 1 (33) ◽  
pp. 43 ◽  
Author(s):  
Verónica Cánovas ◽  
Raúl Medina
Keyword(s):  
Sediment Transport ◽  
Case Studies ◽  
Wave Height ◽  
Surf Zone ◽  
Control Point ◽  
Wave Climate ◽  
Work Design ◽  
Sediment Distribution ◽  
Wave Incidence

Traditional models usually allow fitting the equilibrium beach planform of crenulated beaches knowing wave climate characteristics at a control point. However, sometimes there are shoals or bars in the surf zone which affect surf zone dynamics and longshore sediment distribution, and it is difficult to take into account these elements using those traditional models. A long-term equilibrium beach planform model is proposed here based on sediment transport equations. This model takes into account the sediment transport due to oblique wave incidence and that due to wave height gradient. Two case studies have been studied: a simple pocket beach and a beach which is sheltered by a sandstone bar. Results show the model fits reasonably well the equilibrium beach planform to the shorelines of those beaches. This model is more suitable than traditional models when there are elements affecting surf zone dynamics.

scholarly journals Automotive Radar using AWR2243 Booster Pack

2020 ◽  
Vol 16 (15) ◽  
pp. 132
Author(s):  
Arvind Vishnubhatla
Keyword(s):  
Continuous Wave ◽  
Motor Vehicles ◽  
Single Chip ◽  
Cruise Control ◽  
Automotive Radar ◽  
Emergency Braking ◽  
Wave Sensors ◽  
Evaluation Board ◽  
High Level ◽  
Automated Highway

<p>In developing countries the growth in the number of motor vehicles is the most significant factor in the rise of road fatalities and injuries. It may be observed that 1.35 million people die every year owing to crashes on road. Most of the accidents can be prevented if the events are detected automatically 1-2 seconds in advance. Texas instruments has come up with a new evaluation board AWR2243 having a single chip operating at 76 to 81Ghz having a FMCW transceiver. This can be instrumental in adaptive cruise control, emergency braking and automated highway driving. A FMCW (frequency modulated continuous wave) obtains the range and velocity from a beat signal. Here millimeter-wave sensors use minimal power consumption to sense range and velocity and the required angle.  The device is interfaced to an external DSP host processor which uses a SYNC_IN signal to start the radar frames. The periodicity of the frames is suitability programmed. The processing provides a high level of performance and flexibility. The signal has three parallel transmit chains and four parallel receive chains. Each receive channel has an LNA, mixer, IF filtering, A2D conversion and decimation. A two- dimensional FFT algorithm is implemented on the host DSP processor.</p>

The Design and Implementation of CW Radar Signal Processing

2014 ◽  
Vol 686 ◽  
pp. 343-347
Author(s):  
Jin Tao ◽  
Chun Chen ◽  
Shang Fu Liu ◽  
Qing Wei Han
Keyword(s):  
False Alarm ◽  
Continuous Wave ◽  
Radar Data ◽  
Time Correlation ◽  
Radar Signal ◽  
Wave Radar ◽  
Low Altitude ◽  
Radar Data Processing ◽  
Data Terminal ◽  
Cw Radar

This paper study continuous wave radar data processing algorithm for low altitude detection, it is applied to continuous wave low altitude search radar data terminal, it can realize real-time correlation and track processing for the data of target echo and false alarm false alarm filtering, to get the real targets of track parameters. Finally, through the realization of FPGA, the experimental results achieve the precision of the system.

scholarly journals RAPID DEPLOYMENT AND POST-STORM RECONNAISSANCE OF HURRICANE LAURA

2020 ◽  
pp. 60
Author(s):  
Navid H. Jafari ◽  
Qin Chen ◽  
Jack Cadigan
Keyword(s):  
Storm Surge ◽  
Overland Flow ◽  
Pressure Sensors ◽  
Tropical Storm ◽  
Civil Infrastructure ◽  
Hurricane Rita ◽  
Risks Assessment ◽  
Wave Sensors ◽  
Louisiana Coast ◽  
Rapid Deployment

Hurricane Laura made landfall on the southwest Louisiana coast near Cameron, LA on August 26th. As Laura approached the Louisiana coast, the Coastal Emergency Risks Assessment predicted a storm surge of approximately 5.2 m (17 ft), which marked the strongest surge to impact southwest Louisiana since the catastrophic Hurricane Rita in 2005. As a result, a team led by LSU and NEU mobilized to deploy surge and wave sensors and collect drone imagery at Rockefeller Wildlife Refuge and Cameron, LA on August 25th before the arrival of tropical storm winds. Rockefeller Refuge was selected to measure the capacity of wetlands and breakwaters to attenuate hurricane surge and waves, and pressure sensors were strategically placed at locations of civil infrastructure at Cameron to capture hurricane-induced overland flow (see Fig. 1). After the surge water receded, LSU retrieved the sensors, collected RTK elevation transects and multispectral drone imagery, and surveyed infrastructure damage along the southwest corridor of Louisiana, following the Highway 82 from Abbeville to Cameron.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/IevnFZ2YVfI

scholarly journals Research on Trajectory Planning in Thunderstorm Weather Based on Dynamic Window Algorithm during Approach Segment

2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Li Lu ◽  
Chenyu Liu
Keyword(s):  
Path Planning ◽  
Optimal Path ◽  
Dynamic Environment ◽  
Time Correlation ◽  
Space Time ◽  
Superior Performance ◽  
Time Dynamic ◽  
Moving Obstacles ◽  
Planning Algorithm ◽  
Window Approach

Dynamic window algorithm (DWA) is a local path-planning algorithm, which can be used for obstacle avoidance through speed selection and obtain the optimal path, but the algorithm mainly plans the path for fixed obstacles. Based on DWA algorithm, this paper proposes an improved DWA algorithm based on space-time correlation, namely, space-time dynamic window approach. In SDWA algorithm, a DWA associated with obstacle position and time is proposed to achieve the purpose of path planning for moving obstacles. Then, by setting the coordinates of the initial moving obstacle and identifying safety distance, we can define the shape of the obstacle and the path planning of the approach segment in thunderstorm weather based on the SDWA model was realized. Finally, the superior performance of the model was verified by setting moving obstacles for path planning and selecting the aircraft approach segment in actual thunderstorm weather. The results showed that SDWA has good path-planning performance in a dynamic environment. Its path-planning results were very similar to an actual aircraft performing thunderstorm-avoidance maneuvers, but with more smooth and economical trajectory. The proposed SDWA model had great decision-making potential for approach segment planning in thunderstorm weather.

scholarly journals Surf and Swash Dynamics on Low Tide Terrace Beaches

Coasts ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 73-89
Author(s):  
Ivana M. Mingo ◽  
Rafael Almar ◽  
Laurent Lacaze
Keyword(s):  
Energy Dissipation ◽  
Surf Zone ◽  
Wave Climate ◽  
Swash Zone ◽  
Dean Number ◽  
Incoming Wave ◽  
Common View ◽  
Wave Energy Dissipation ◽  
Equilibrium Beach Profile ◽  
High Dynamics

Low tide terrace (LLT) beaches are characterised by a moderately steep beach face and a flat shallow terrace influencing the local hydro-morphodynamics during low tide. The upper beachface slope (β) and the terrace width (Lt) are the main morphological parameters that define the shape of LTT cross-shore beach profiles. This work aims at better understanding the behaviour of β and Lt and their link with the incoming wave forcing. For this purpose, our results are based on 3.5 years times series of daily beach profiles and wave conditions surveys at two different microtidal LTT beaches with similar sediments size but different wave climate, one at Nha Trang (Vietnam) and the other one at Grand Popo (Benin). While they look similar, two contrasting behaviour were linked to two sub-types of LTT regimes: the first one is surf regulated beaches (SRB) where the swash zone is highly regulated by the surf zone wave energy dissipation on the terrace, and the second is swash regulated beaches (SwRB) acting in more reflective regime where the terrace is not active and the energy dissipation is mainly produced in the swash zone, the terrace becomes a consequences of the high dynamics in the swash zone. Finally, extending the common view of an equilibrium beach profile as a power law of the cross-shore distance, the ability of a simple parametrized cubic function model with the Dean number as unique control parameters is proposed and discussed. This simple model can be used for the understanding of LLT environments but it can not be extended to the whole beach spectrum.

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