Search
Filters
total: 598
filtered: 523
Search results for: SHALLOW COASTAL WATERS
-
Reliable underwater communication system for shallow coastal waters
PublicationThis paper presents a reliable and robust low data rate spread spectrum approach which is implemented in the acoustic underwater communication system for shallow coastal waters. It shows operation assumptions of spread spectrum techniques based on the wellknown Shannon equation. It describes two methods of spread spectrum: frequency hopping spread spectrum and direct sequence spread spectrum; their block diagram and their characteristics...
-
Synchronization system for underwater acoustic communications using in shallow waters
PublicationA reliable synchronization system of the transmitted data frame has a significant impact on the efficiency of the underwater communication system. This applies in particular to communication systems dedicated to work in shallow waters, where the phenomenon of multipath permanently occurs. To overcome these difficulties, the concept of a synchronization system consisting of two broadband signals of opposite monotonicity was presented....
-
On Some Aspects of Fish Target Strength Estimation in Shallow Waters
PublicationThe theory of acoustic surveys for determining fish abundance are well established in fishery acoustics. The origins of the estimation are related to overcoming the problem of unknown position of target in the beam using statistical inversion. Although recently researchers use more sophisticated echosounders that provides more informative data allowing for direct solution it is known that the results are biased due to not ideally...
-
Canthaxanthin in recent sediments as an indicator of heterocystous cyanobacteria in coastal waters
Publication -
Safety enhancement using 3D multibeam sonar imaging in shallow waters areas
PublicationSonary wielowiazkowe wykorzystanee byc moga do poprawy bezpieczenstwa zeglugi na obszarach wod plytkich. Dzieki istotnej poprawie rozdzielczosci horyzontalnej i wertykalnej pomiarow zastosowane byc moga do obrazowania wod plytkich szczegolnie niebezpiecznych pod wzgledem nawigacyjnym.
-
Monitoring of organic pollutants in coastal waters of the Gulf of Gdańsk, Southern Baltic.
PublicationPrzedstawiono zmiany zawartości zanieczyszczeń organicznych (np. VOC, PAH, PCB, chlorofenoli) w wodach Zatoki Gdańskiej na przestrzeni 5-ciu lat. Zawartość VOX i VOC zmieniała się od kilku ngdm-3 do kilkuset ngdm-3, podczas gdy zawartość chlorofenoli fenoksykwasów była na poziomie kilku ngdm-3. W większości próbek nie wykryto PCB.
-
The sensitivity of bacteria to heavy metals in presence of mineral ship motor oil in coastal marine sediments and waters.
PublicationThe sensitivity of bacteria, isolated from coastal marine sediments and waters of Sopot beach, Gdańsk Bay (Poland), to heavy metals in the presence of mineral ship motor oil were studied. All isolated heterotrophic bacteria were resistant to the 0.1 mM lead concentration occurring in the environment. Metal resistance of bacteria isolated from coastal water was strongly related to mineral ship motor oil concentration. At 0.1% mineral...
-
Modelling the impact of the agricultural holdings and land-use structure on the quality of inland and coastal waters with an innovative and interdisciplinary toolkit
PublicationThe changes taking place in the marine coastal zones are extremely important, as about 40% of the human population currently lives in the coastal areas (within 100 kilometres of the coastline) increasing anthropogenic pressure on the marine ecosystems. Agriculture is a significant source of nutrients to the marine environment that increase hypoxia, eutrophication and may pose a threat to the services provided by ecosystems. In...
-
Comparison of PCBs and PAHs levels in European coastal waters using mussels from the Mytilus edulis complex as biomonitors
PublicationMussels from the Mytilus edulis complex were used as biomonitors for two groups of organic pollutants: polychlorinated biphenyls (PCBs, congeners: 28, 52, 101, 118, 138, 153 and 180) and polycyclic aromatic hydrocarbons (PAHs, naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene,...
-
Modelling the impact of the agricultural holdings and land-use structure on the quality of inland and coastal waters with an innovative and interdisciplinary toolkit
Publication -
Empirical Model for Phycocyanin Concentration Estimation as an Indicator of Cyanobacterial Bloom in the Optically Complex Coastal Waters of the Baltic Sea
Publication -
A New Approach for Investigating the Impact of Pesticides and Nutrient Flux from Agricultural Holdings and Land-Use Structures on Baltic Sea Coastal Waters
PublicationKnowledge related to land-use management impacts on the Baltic Sea ecosystem is limited. The constant release of pollutants into water bodies has resulted in water quality degradation. Therefore, only the innovative approaches integrated with research will provide accurate solutions and methods for proper environment management and will enable understanding and prediction of the impacts of land-use in the Baltic Sea region. Modelling...
-
Application of Web-GIS and Geovisual Analytics to Monitoring of Seabed Evolution in South Baltic Sea Coastal Areas
PublicationRegular surveys of coastal zone seabed deliver important information about geomorphologic processes such as silting of waterways. The recent introduction of the Sentinel series of sensors has allowed for the use of satellite sensing for shallow bathymetry morphology monitoring. In this context, this article presents a dedicated Geographic Information System for Baltic Sea shallow water depth monitoring on the basis of Sentinel-2...
-
An analytical four-layer horizontal electric current dipole model for analysing underwater electric potential in shallow seawater
PublicationThe paper presents a new analytical four‑layer (air–water–bottom–non‑conductive layer) horizontal electric dipole model which allows an accurate approximation of ship’s Underwater Electric Potential (UEP) from a sufficient depth in shallow coastal marine waters. The numerical methods, usually Finite Element Method (FEM) or Boundary Elements Method (BEM), are typically used to estimate the electric field and the distribution of...
-
Method for determining of shallow water depths based on data recorded by UAV/USV vehicles and processed using the SVR algorithm
PublicationBathymetric measurements in waters shallower than 1 m are necessary to monitor seafloor relief changes in the coastal zone. This is especially important for ensuring the safety of navigation, navigation efficiency, as well as during the design and monitoring of hydrotechnical structures. Therefore, the aim of this article is to present a method for determining of shallow water depths based on data recorded by Unmanned Aerial Vehicle...
-
Using Fast Frequency Hopping Technique to Improve Reliability of Underwater Communication System
PublicationAcoustic underwater communication systems designed to work reliably in shallow coastal waters must overcome major limitations such as multipath propagation and the Doppler effect. These restrictions are the reason for the complexity of receivers being built, whose task is to decode a symbol on the basis of the received signal. Additional complications are caused by the low propagation speed of the acoustic wave in the water and...
-
The Examination of the Upper Layers of the Seabed by the Means of the Acoustic Methods
PublicationPropagation of acoustic waves in the sea, in particular in shallow sea, depends on several factors. The basic of them are source power and frequency of acoustic waves, spatial distribution inhomogeneous medium in which acoustic wave propagates, and distributions of speed of sound and density of seawater. The coastal conditions, which limit water medium from above (free surface of the sea) and from bottom (the seabed), are no less...
-
Determining the Seasonal Variability of the Territorial Sea Baseline in Poland (2018–2020) Using Integrated USV/GNSS/SBES Measurements
PublicationThe Territorial Sea Baseline (TSB) allows coastal states to define the maritime boundaries, such as: contiguous zone, continental shelf, exclusive economic zone and territorial sea. Their delimitations determine what rights (jurisdiction and sovereignty) a given coastal state is entitled to. For many years, the problem of delimiting baseline was considered in two aspects: legal (lack of clear-cut regulations and different interpretations)...
-
The possibility of the application of a potentiometric sensor with all-solid-state electrodes for the quality control of different natural waters
PublicationThe quality of various natural waters was examined by a new potentiometric sensor with six all solid state electrodes containing an appropriate lipophilic compound in a polymer membrane. Physicochemical parameters such as conductivity and acidity of tested waters were also tested. All waters were neutral or slightly alkaline and contained different ions (e.g., Cl–) due to the place of their sampling (a coastal zone and a moraine...
-
Shallow Water Experiment of OFDM Underwater Acoustic Communications
PublicationThe large variability of communication properties of underwater acoustic channels, and especially the strongly varying instantaneous conditions in shallow waters, is a challenge for the designers of underwater acoustic communication (UAC) systems. The use of phase modulated signals does not allow reliable data transmission through such a tough communication channel. However, orthogonal frequency-division multiplexing (OFDM), being...
-
Environmental aspects of coastal earth structures made of soil-ash composites
PublicationThis paper presents an innovative technology of building the coastal dams with the use of soil-ash composites. A natural- scale test stand and results of the performed environmental tests are presented ; they have been compared with standards for purity of soils and waters. Also, an analysis of the obtained results and discussion of trends and anomalies in the observations, are given.
-
Bringing Bathymetry LiDAR to Coastal Zone Assessment: A Case Study in the Southern Baltic
PublicationOne of the major tasks in environmental protection is monitoring the coast for negative impacts due to climate change and anthropopressure. Remote sensing techniques are often used in studies of impact assessment. Topographic and bathymetric procedures are treated as separate measurement methods, while methods that combine coastal zone analysis with underwater impacts are rarely used in geotechnical analyses. This study presents...
-
Testing OFDM Transmission Schemes for Shallow Water Acoustic Communications
PublicationLarge variability of communication properties of underwater acoustic channels, and especially strongly varying instantaneous conditions in shallow waters, is a tough challenge for the designers of underwater acoustics communication (UAC system. There is a need for developing adaptive signaling schemes that would dynamically optimize signal parameters in both physical and link layers of communication protocols. The orthogonal frequency...
-
Automatic classification and mapping of the seabed using airborne LiDAR bathymetry
PublicationShallow coastal areas are among the most inhabited areas and are valuable for biodiversity, recreation and the economy. Due to climate change and sea level rise, sustainable management of coastal areas involves extensive exploration, monitoring, and protection. Current high-resolution remote sensing methods for monitoring these areas include bathymetric LiDAR. Therefore, this study presents a novel methodological approach to assess...
-
Wake-Up Receiver for Underwater Acoustic Communication Using in Shallow Water
PublicationA data frame transmitted over the underwater acoustic channel usually begins with a preamble. Therefore, underwater communication systems have a dedicated receiver that constantly listens to the preamble signals. A receiver that is to work effectively in shallow waters must have solutions that effectively reduce the impact of the permanently occurring multipath propagation. The article presents a solution based on complementary...
-
Multibeam Echosounder and LiDAR in Process of 360-Degree Numerical Map Production for Restricted Waters with HydroDron
PublicationIn order to increase the safety of inland navigation and facilitate the monitoring of the coastal zone of restricted waters, a model of multi-sensory fusion of data from hydroacoustic and optoelectronic systems mounted on the autonomous survey vessel HydroDron will be developed. In the research will be used the LiDAR laser scanner and multibeam echosounder. To increase the visual quality and map accuracy, additionally side scan...
-
Mercury concentration in the sediments as a function of changing climate in coastal zone of Southern Baltic Sea – preliminary results
PublicationMercury, despite of its many uses in industry, is also highly toxic. It is highly neurotoxic, and because of the ability of mercury to penetrate placental barrier, in some countries ban on predatory fish consumption (the main route of mercury into human organism) by pregnant women was introduced. There are very little publications describing the consequences of weather anomalies on contaminants cycles. No research was published...
-
Integration Data Model of the Bathymetric Monitoring System for Shallow Waterbodies Using UAV and USV Platforms
PublicationChanges in the seafloor relief are particularly noticeable in shallow waterbodies (at depths up to several metres), where they are of significance for human safety and environmental protection, as well as for which the highest measurement accuracy is required. The aim of this publication is to present the integration data model of the bathymetric monitoring system for shallow waterbodies using Unmanned Aerial Vehicles (UAV) and...
-
Performance of Coherent Modulation Scheme Used in Acoustic Underwater Communication System
PublicationThe development of an acoustic underwater communication system for shallow waters is still a big scientificand construction challenge. Currently, non-coherent modulations in combination with strong channel coding are used to achieve reliable communication with low rate in such a channel. To obtain transmission with a higher transmission rate, it is required to use coherent modulation. This paper presents the assumptions of such...
-
Underwater acoustic communication system using broadband signal with hyperbolically modulated frequency
PublicationThe implementation of reliable acoustic underwater communication in shallow waters is a scientific and engineering challenge, mainly due to the permanent occurrence of the multipath phenomenon. The article presents the concept of a transmission system using a broadband signal with hyperbolically modulated frequency (HFM) to transmit data symbols and synchronize data frames. The simulation tests were carried out in channels with...
-
Seasonal changes of mercury speciation in the coastal sediments
PublicationPurpose Mercury speciation in sediments is linked to environmental conditions and processes. Domination of particular mercury species depends on its source, displays considerable seasonal behavior, and may be further modified due to oxygen levels, icing conditions, or the input of fresh organic matter. The purpose of this study was to examine the coastal area of the Gulf of Gdańsk in terms of mercury contamination and the influence...
-
Observations of presumable groundwater seepage occurrence in Puck Bay (the Baltic Sea)
PublicationWe report the results of recent field measurements of seawater thermohaline structure and transparency carried out in early summer 2014 in Puck Bay. Near-bottom, less saline waters occurred almost in the entire study area. Their occurrence in the shallow part of Puck Bay was accompanied by an increase in the seawater transparency. The most likely explanation of these observations is a submarine fresh groundwater discharge.
-
Analysis of Methods for Determining Shallow Waterbody Depths Based on Images Taken by Unmanned Aerial Vehicles
PublicationHydrographic surveys enable the acquisition and processing of bathymetric data, which after being plotted onto nautical charts, can help to ensure safety of navigation, monitor changes in the coastal zone, and assess hydro-engineering structure conditions. This study involves the measurement of waterbody depth, identification of the seabed shape and geomorphology, the coastline course, and the location of underwater obstacles....
-
Mathematical Modeling of Ice Thrusting on the Shore of the Vistula Lagoon (Baltic Sea) and the Proposed Artificial Island
PublicationCoastal lagoons are inland and shallow water bodies, separated from the ocean by a barrier. In cold regions, ice phenomena in shallow water coastal lagoons occur every winter season. Ice is predominantly formed on the surface due to density stratification and surface cooling. The ice dynamics in such areas are dominantly affected by winds. Water dynamics also cause ice movement, but due to the large areal scale of lagoons, the...
-
INVESTIGATION INTO INTERFEROMETRIC SONAR SYSTEM ACCURACY
PublicationThe results of the accuracy measurements of phase differencing bathymetric sonar (PDBS) system in shallow waters are presented in the article. The measurement results were compared with the theoretical calculations for sonar system accuracy and international standards for hydrographic surveys. The proposed formulas enable to assess a priori sonar system performance using system quality factor (SQF), which takes into account influence...
-
Investigation of the vertical distribution of the sound speed of the Gulf of Gdansk in the years 2000-2010
PublicationThe conditions of the acoustic wave propagation in the southern Baltic are much more complex than in other shallow waters. In the typical shallow water, seasonal changes in acoustical conditions in the upper layer, of the depth of about 60-70 m, are observed. They are caused by variation of the annual meteorological conditions. Most often, in the deep water layer, acoustical conditions are stable throughout the year. However, in...
-
Assessment of the Steering Precision of a Hydrographic Unmanned Surface Vessel (USV) along Sounding Profiles Using a Low-Cost Multi-Global Navigation Satellite System (GNSS) Receiver Supported Autopilot
Publicationhe performance of bathymetric measurements by traditional methods (using manned vessels) in ultra-shallow waters, i.e., lakes, rivers, and sea beaches with a depth of less than 1 m, is often difficult or, in many cases, impossible due to problems related to safe vessel maneuvering. For this reason, the use of shallow draft hydrographic Unmanned Surface Vessels (USV) appears to provide a promising alternative method for performing...
-
Microbial and chemical quality assessment of the small rivers entering the South Baltic. Part II: Case study on the watercourses in the Puck Bay catchment area
PublicationDue to its location, Puck Bay is an area particularly vulnerable to pollution of anthropogenic origin. The aim of the study was to assess the water quality of small watercourses entering the inner part of Puck Bay. The paper presents the results of chemical and microbiological analyses of 10 rivers and canals at their estuaries located on the western shore of the internal Puck Bay. The following environmental parameters were analyzed:...
-
Methodology for the Correction of the Spatial Orientation Angles of the Unmanned Aerial Vehicle Using Real Time GNSS, a Shoreline Image and an Electronic Navigational Chart
PublicationUndoubtedly, Low-Altitude Unmanned Aerial Vehicles (UAVs) are becoming more common in marine applications. Equipped with a Global Navigation Satellite System (GNSS) Real-Time Kinematic (RTK) receiver for highly accurate positioning, they perform camera and Light Detection and Ranging (LiDAR) measurements. Unfortunately, these measurements may still be subject to large errors-mainly due to the inaccuracy of measurement of the optical...
-
Mobile inventory system for hydrotechnical objects using data from multiple sensors operating simultaneously
PublicationThe knowledge of the location, shape and other characteristics of spatial objects in the coastal areas has a significant impact on the functioning of ports, shipyards, and other water-infrastructure facilities, both offshore and inland. Therefore, measurements are taken of the underwater part of the waterside zone, which means the bottom of water and other underwater objects (e.g. breakwaters, docks, etc.), and objects above the...
-
Distribution and extent of benthic habitats in Puck Bay (Gulf of Gdańsk, southern Baltic Sea)
PublicationThe majority of the southern Baltic Sea seabed encompasses homogenous soft-bottom sediments of limited productivity and low biological diversity, but shallow productive areas in the coastal zone such as wetlands, vegetated lagoons and sheltered bays show a high variety of benthic habitat types offering favourable biotopic conditions for benthic fauna. Within Polish marine areas, semi-enclosed Puck Bay (the western part of the...
-
Simulations of freshwater lens recharge and salt/freshwater interfaces using the HYDRUS and SWI2 packages for MODFLOW
PublicationThe paper presents an evaluation of the combined use of the HYDRUS and SWI2 packages for MODFLOW as a potential tool for modeling recharge in coastal aquife rs subject to saltwater intrusion. The HYDRUS package for MODFLOW solves numerically the one-dimensional form of the Richards equation describing water flow in variably- saturated media. The code computes groundwater recharge to or...
-
A High-Arctic flow-through lake system hydrochemical changes: Revvatnet, southwestern Svalbard (years 2010–2018)
PublicationLake ecosystems are strongly coupled to features of their surrounding landscapes such as geomorphology, lithology, vegetation and hydrological characteristics. In the 2010–2018 summer seasons, we investigated an Arctic flow-through lake system Revvatnet, located in the vicinity of the coastal zone of Hornsund fjord in Svalbard, characterising its hydrological properties and the chemical composition of its waters. The lake system...
-
First evaluation of wastewater discharge influence on marine water contamination in the vicinity of Arctowski Station (Maritime Antarctica)
PublicationIn Antarctica,waste is generatedmainly during scientific research programmes and related logistics. In this study, the impact ofwastewater on the western shore of Admiralty Baywas investigated during austral summer in 2017 and 2019. A range of physicochemical parameters and the presence of selected trace metals, formaldehyde and different groups of surfactants were determined in wastewater coming from Arctowski Station and in nearby coastal...
-
Review of Shoreline Extraction Methods from Aerial Laser Scanning
PublicationAutonomous technologies are increasingly used in various areas of science. The use of unmanned vehicles for hydrographic surveys in shallow coastal areas requires accurate estimation of shoreline position. This is a nontrivial task, which can be performed using a wide range of sensors and methods. The aim of the publication is to review shoreline extraction methods based solely on data from aerial laser scanning (ALS). This narrative...
-
The development of an underwater telephone for digital communication purposes
PublicationThe underwater telephone HTL-10 has been designed to provide voice and data communication between helicopter and submarines using acoustic waves. It works in a half-duplex mode and uses analogue power-efficient modulation in the form of a single side-band, suppressed carrier, in a wide range of frequencies. It generates the transmitted signal, and processes the received signals. It is implemented with the use of digital signal...
-
Habitat-related patterns of soft-bottom macrofaunal assemblages in a brackish, low-diversity system (southern Baltic Sea)
PublicationCoastal areas provide a high variety of sedimentary habitats that influence the structure of resident fauna even on small geographical scales. Therefore, examinations of spatial variations in benthic assemblages require background knowledge of the environmental and biotic heterogeneity of habitats in order to understand ecological processes in such areas. The effect of habitat-related abiotic and biological variables on macrofaunal...
-
Wireless Link Selection Methods for Maritime Communication Access Networks—A Deep Learning Approach
PublicationIn recent years, we have been witnessing a growing interest in the subject of communication at sea. One of the promising solutions to enable widespread access to data transmission capabilities in coastal waters is the possibility of employing an on-shore wireless access infrastructure. However, such an infrastructure is a heterogeneous one, managed by many independent operators and utilizing a number of different communication...
-
Integrated information and prediction Web Service WaterPUCK General concept
PublicationIn this paper, general concept of a new method as ‘Integrated information and prediction Web Service WaterPUCK’ for investigation influence of agricultural holdings and land-use structures on coastal waters of the southern Baltic Sea is presented. WaterPUCK Service is focused on determination of the current and future environmental status of the surface water and groundwater located in the Puck District (Poland) and its impact...
-
Innovative Urban Blue Space Design in a Changing Climate: Transition Models in the Baltic Sea Region
PublicationWaterfront areas in cities are subject to constant changes. The desire to integrate the transformed waterside areas with the urban fabric involves shaping high-quality public spaces related to water, which are often referred to as urban blue spaces (UBS). The aim of the research was to examine the transformation processes of urban waterfront areas in the Baltic Sea Region and identify emerging transition models and types of blue...