Wave Measurements

Purpose of the present report is the summary of the experimental campaign performed at INSEAN facilities. This campaign has been oriented to analyze the classical wave measurement systems and, furthermore, to validate the results of the numerical models. A devoted paragraph describes the main features of a new innovative and non intrusive methodology for the wave measurements aimed to perform both model and ship scale trials

Application of X-Band Wave Radar for Coastal Dynamic Analysis: Case Test of Bagnara Calabra (South Tyrrhenian Sea, Italy)

Sea state knowledge has a key role in evaluation of coastal erosion, the assessment of vulnerability and potential in coastal zone utilization, and development of numerical models to predict its evolution. X-band radar measurements were conducted to observe the spatial and temporal variation of the sea-state parameters along a 3 km long sandy-gravelly pocket beaches forming a littoral cell on Bagnara Calabra. We produced a sequence of 1000 images of the sea state extending offshore up to 1 mile. The survey has allowed monitoring the coastline, the directional wave spectra, the sea surface current fields, and the significant wave heights and detecting strong rip currents which cause scours around the open inlets and affect the stability of the submerged reef-type breakwaters. The possibility to validate the data acquired with other datasets (e.g., LaMMA Consortium) demonstrates the potential of the X-band radar technology as a monitoring tool to advance the understanding of the linkages between sea conditions, nearshore sediment dynamics, and coastal change. This work proves the possibility to obtain relevant information (e.g., wave number, period, and direction) for evaluation of local erosion phenomena and of morphological changes in the nearshore and surf zone

Developing a remote sensing system based on X-band radar technology for coastal morphodynamics study

New data processing techniques are proposed for the assessment of scopes and limitations from radar-derived sea state parameters, coastline evolution and water depth estimates. Most of the raised research is focused on Colombian Caribbean coast and the Western Mediterranean Sea. First, a novel procedure to mitigate shadowing in radar images is proposed. The method compensates distortions introduced by the radar acquisition process and the power decay of the radar signal along range applying image enhancement techniques through a couple of pre-processing steps based on filtering and interpolation. Results reveal that the proposed methodology reproduces with high accuracy the sea state parameters in nearshore areas. The improvement resulting from the proposed method is assessed in a coral reef barrier, introducing a completely novel use for X-Band radar in coastal environments. So far, wave energy dissipation on a coral reef barrier has been studied by a few in-situ sensors placed in a straight line, perpendicular to the coastline, but never been described using marine radars. In this context, marine radar images are used to describe prominent features of coral reefs, including the delineation of reef morphological structure, wave energy dissipation and wave transformation processes in the lagoon of San Andres Island barrier-reef system. Results show that reef attenuates incident waves by approximately 75% due to both frictional and wave breaking dissipation, with an equivalent bottom roughness of 0.20 m and a wave friction factor of 0.18. These parameters are comparable with estimates reported in other shallow coral reef lagoons as well as at meadow canopies, obtained using in-situ measurements of wave parameters.DoctoradoDoctor en Ingeniería Eléctrica y Electrónic

Application of marine radar to monitoring seasonal and event-based changes in intertidal morphology

This paper demonstrates the application of marine radar and a newly developed waterline mapping technique to the continued surveillance and monitoring of inter- and intra-annual intertidal morphological change, thus capturing new detail on coastal system behaviours. Marine radar data from 2006 to 2009 are used to create a sequence of waterline elevation surveys that show clear morphological evolution of two different sites in the Dee estuary, UK. An estimate of volumetric change was made at two locations: West Hoyle sandbank and the NW Wirral beach. Both sites exhibited a similar cyclic pattern of volumetric change, with lowest volumes in autumn and winter, respectively. The average beach elevations above Admiralty Chart Datum clearly reflect the observed change in sediment volume, with reduced elevations in winter and increased elevations in summer, suggesting a trend of high-energy storm waves in autumn and winter that remove sediment and simultaneously moderate the vertical dimension of bedforms in the intertidal area. Data at this temporal and spatial scale are not easily obtainable by other current remote sensing techniques. The use of marine radar as a tool for quantifying coastal change over seasonal and event timescales in complex hydrodynamic settings is illustrated. Specifically, its unique application to monitoring areas with dynamic morphology or that is vulnerable to erosion and/or degradation by storm events is exemplified

THE USE OF MARINE RADAR FOR INTERTIDAL AREA SURVEY AND MONITORING COASTAL MORPHOLOGICAL CHANGE

Surveying and monitoring the dynamic morphology of intertidal areas is a logistically challenging and expensive task, due to their large area and complications associated with access. This thesis describes a contribution to the nearshore survey industry; an innovative methodology is developed and subsequently applied to marine radar image data in order to map topography within the intertidal area. This new method of intertidal topographical mapping has a reasonable spatial resolution (5 m) and operates over a large radial range (~4 km) with the required temporal resolution to observe both event-based and long-term morphological change (currently bi-weekly surveys). This study uses nearly three years of radar image data collected during 2006-2009 from an installation on Hilbre Island at the mouth of the Dee estuary, northwest UK. The development of the novel 'radar waterline method' builds on previous waterline techniques and improves upon them by moving the analysis from the spatial to the temporal domain, making the analysis extremely robust and more resilient to poor quality image data. Results from radar topographical surveys are compared to those of a LiDAR survey during October 2006. The differences compare favourably across large areas of the intertidal zone, within the first kilometre 97% of radar-derived elevations lie within 1 m of LiDAR estimations. Concentrations of poor estimations are seen in areas that are shown to be shadowed from the radar antenna or suffering from pooling water during the ebb tide. The full three-year dataset is used to analyse changing intertidal morphology over that time period using radar-derived surveys generated every two weeks. These surveys are used to perform an analysis of changing sediment volume and mean elevation, giving an indication of beach 'health' and revealing a seasonal trend of erosion and accretion at several sites across the Dee estuary. The ability of the developed technique to resolve morphological changes resulting from storm events is demonstrated and a quantification of that impact is provided. The application of the technique to long-range (7.5 km) marine radar data is demonstrated in an attempt to test the spatial and operational limitations of this new method. The development of a mobile radar survey platform, the Rapidar allows remote areas to be surveyed and provides a platform for potential integration with other survey instruments. A description of the potential application to coastal management and monitoring is presented. Areas of further work intended to improve vertical elevation accuracy and robustness are proposed. This contribution provides a useful tool for coastal scientists, engineers and decision-makers interested in the management of coastal areas that will form part of integrated coastal management and monitoring operations. This method presents several key advantages over traditional survey techniques including; the large area of operation and temporal resolution of repeat surveys, it is limited primarily by topographical shadowing and low wind conditions limiting data collection

The use of lasers for hydrographic studies

The utilization of remote laser sensors in water pollution detection and identification, coastal environmental monitoring, and bathymetric depth sounding, is discussed. q

Seventh International Symposium "Monitoring of Mediterranean Coastal Areas. Problems and Measurement Techniques"

The Seventh International Symposium Monitoring of Mediterranean Coastal Areas. Problems and Measurement Techniques (Livorno, Italy June 19-20-21, 2018) was organized by the CNR-IBIMET in collaboration with the City of Livorno, the LEM Foundation, the FCS Foundation and the Compagnia dei Portuali di Livorno, with the patronage by Accademia Nazionale dei Lincei, Accademia dei Georgofili, The University of Florence, the Tuscany Region and the North Tyrrhenian Sea Port System Authority. The Symposium, in which scholars from all over the Mediterranean basin participated, was an opportunity to illustrate new proposals and to promote actions to protect the Mediterranean coastal marine environment. In particular, the event was characterized by the search for technical and instrumental solutions to problems related to: energy production in the coastal area, morphology and evolution of coastlines, flora and fauna of the littoral system, management and integrated coastal protection, coastline geography, human influence on coastal landscape

Department of Defense Dictionary of Military and Associated Terms

The Joint Publication 1-02, Department of Defense Dictionary of Military and Associated Terms sets forth standard US military and associated terminology to encompass the joint activity of the Armed Forces of the United States. These military and associated terms, together with their definitions, constitute approved Department of Defense (DOD) terminology for general use by all DOD components