Christos Kastrisios

University of New Hampshire | UNH · Center for Coastal and Ocean Mapping/Joint Hydrographic Center

This paper is concerned with the implementation and realisation of a Worldwide Electronic Navigational Charts Database (WEND), adopted by the International Hydrographic Organization (IHO) and its members in supporting marine navigation. It identifies the issue of gaps and overlaps between adjoining Electronic Navigational Charts (ENCs) and explores...

The delimitation of maritime zones and boundaries foreseen by the United Nations Convention on the Law of the Sea is a factor of economic growth, effective management of the coastal and ocean environment and the cornerstone for maritime spatial planning. Maritime boundaries form the outermost limits of coastal states and their accurate computation...

One of the fundamental concepts of the Convention on the Law of the Sea is that of the baselines, where from the breadth of the maritime zones is measured. Baselines, delimiting the land and internal waters from the sea, can be any combination of normal, straight, archipelagic or bay-closing lines. The determination of the coastline indentations at...

The interests, responsibilities and opportunities of states to provide infrastructure and resource management are not limited to their land territory but extend to marine areas as well. So far, although the theoretical structure of a Marine Administration System (MAS) is based on the management needs of the various countries, the marine terms have...

Voronoi tessellation, and its dual the Delaunay triangulation, provide a cohesive framework for the study and interpretation of phenomena of geographical space in two and three dimensions. The planar and spherical solutions introduce errors in the positional accuracy of both Voronoi vertices and Voronoi edges due to errors in distance computations...

Current nautical chart generalization methods are notably labor intensive, requiring significant levels of human intervention to compile, update, and maintain chart products. The ideal situation would be a fully automated solution for generating nautical charts seamlessly from a comprehensive database, on demand, at the appropriate scale, at the po...

The oceans remain one of Earth’s most enigmatic frontiers, with approximately 75% of the world’s oceans still unmapped. To create a seamless digital bathymetric model (DBM) from sparse bathymetric datasets, interpolation is employed, but this introduces uncertainties of unknown nature. This study aims to estimate and characterize these uncertaintie...

ENC symbols in the IHO Portrayal catalogue follow the IHO specific SVG format. Development of simple symbols (e.g., lines or dots) is straightforward and can be accomplished by manipulating the XML code of similar, existing, ENC symbology. However, the development of more complex symbols directly into the IHO format can become cumbersome. For compl...

Cartographic sounding selection is a constraint-based bathymetric generalization process for identifying navigationally relevant soundings for nautical chart display. Electronic Navigational Charts (ENCs) are the premier maritime navigation medium and are produced according to international standards and distributed around the world. Cartographic g...

Sudden changes in a vessel's path are common, complicating efforts to predict future behavior. In this work, we leverage existing traffic to develop an algorithm that makes informed trajectory predictions. Our method begins with analyzing historical maritime traffic using AIS data from vessels in southern New England. This analysis culminates in cr...

The compilation of Electronic Navigational Charts (ENCs) requires significant amount of time, labor-intensive efforts, and cost. Despite the advancements in technology and the various research efforts, generalization tasks are still performed manually or semi-manually with expected human errors. The dramatic increase in the amount of data that is c...

Significant amounts of labor-intensive effort and time are needed for compiling and maintaining Electronic Navigation Charts (ENCs). The great amount of data collected with high-resolution systems that are being delivered to the charting divisions along with initiatives within the divisions, such as the Office of Coast Survey (OCS)/ Marine Chart Di...

This work presents the development of new symbology for S-1xx Product Specifications.

The oceans are truly Earth's last great unknown. With about 75% of the world's ocean and 53% of the U.S. ocean, coastal, and Great Lakes waters unmapped, interpolation across large distances is typically required among sparse bathymetric datasets/measurements in order to fill the data gaps and create a definitive model of the seafloor. As with any...

Electronic Navigational Chart (ENC) data are essential for safe maritime navigation and have multiple other uses in a wide range of enterprises. Charts are relied upon to be as accurate and as up-to-date as possible by the vessels moving vast amounts of products to global ports each year. However, cartographic generalization processes for updating...

A strategic instrument for the sustainable conservation of the fragile marine ecosystem is the designation of Marine Protected Areas (MPAs), within which various regulations exist for the protection of highly vulnerable species and habitats. These regulations can be depicted on Electronic Navigational Charts (ENCs) based on the new International Hy...

Nautical charts are compiled with bathymetric data that differ in the year and method collected over areas varying from stable to mobile seafloor. Data quality on Electronic Navigational Charts (ENCs) is mainly encoded as an overlay of polygonal regions, each assigned a Category Zone of Confidence (CATZOC) based on the positional and attribute accu...

Zones of Confidence (ZOC) are used with Electronic Navigational Charts (ENCs) to inform mariners about the confidence the producing nation places in bathymetric data. A major concern with the ZOC concept has been the utilized symbology with glyphs consisting of stars. Due to its recognized deficiencies, star symbology has been rejected for use with...

This paper discusses a variety of next-generation data products for marine navigation, many of which are encompassed by existing or planned S-100 standards developed by the International Hydrograph Organization. This includes electronic charts, bathymetric surfaces, shoreline lidar, and marine traffic and infrastructure features extracted from text...

Measurements of the depth of the seabed vary widely in both horizontal and vertical accuracy. To convey this information to mariners, Zones of Confidence (ZOC) are defined for charts. A mosaic of ZOCs can be represented as a chart overlay. This study evaluates two novel designs for textures to represent ZOCs. Both use textures with countable elemen...

Unlike land routing, sea navigation takes place in "free-space", not constrained to strict road networks. To ensure safety of passage, mariners tend to use commonly traveled routes. Nautical and routing charts provide information regarding dangers to navigation and shipping routes and distances between major ports, however they are often outdated o...

Geospatial data may vary in quality in accuracy, precision, completeness, and consistency in space, time, and theme. Geospatial data quality allows producers to evaluate and report how well a dataset meets the criteria set forth in the product specification and users to assess fitness for use for a particular application. Working with data quality...

Airborne lidar bathymetry (ALB) and multi-beam echo-sounders (MBES) are two commonly used methods employed by the hydrographic community for bathymetric data collection. Although these technologies can collect high resolution and accurate depth data, they present some limitations related to whether, cost, time, and survey difficulties in near-shore...

This work aims to address the gap in the current IHO S-122 Marine Protected Areas (MPAs) product specification that lacks portrayal. It presents a set of intuitive pictorial symbols for the MPA categories representative of the endangered species, historical or cultural submerged sites, and for depicting Vessel Traffic Service Areas within the MPA z...

Current methods for nautical charts generalization are strongly human interactive and time-consuming. Significant amounts of effort are needed for generalizing, compiling, updating, maintaining, and consistency checking those products. The ideal situation would be a fully automated solution for generating products on demand, at the right scale, at...

Cartographic sounding selection, the process of identifying navigationally relevant soundings for chart-display, is a time-consuming generalization process in the chart production workflow. Advances in bathymetric data collection and processing techniques are resulting in higher resolution data, which compounds the bottleneck of sounding selection....

Coastal nations, through their dedicated Hydrographic Offices (HOs), have the obligation to provide nautical charts for the waters of national jurisdiction in support of safe maritime navigation. Accurate and reliable charts are essential to seafarers whether for commerce, defence, fishing, or recreation. Since navigation can be an international ac...

The Zones of Confidence (ZOC) is a composite data quality indicator used in Electronic Navigational Charts. Accident reports show that failing to account for chart data quality can result in maritime accidents and loss of life. ZOC overlays are intended to help mariners in identifying potential seafloor hazards and in plotting routes safe for the v...

Marine Spatial Data Infrastructure (MSDI), the extension of terrestrial Spatial Data Infrastructure to the marine environment, is a type of cyberinfrastructure that facilitates the discovery, access, management, distribution, reuse, and preservation of hydrospatial data. MSDIs provide timely access to data from public and private organizations of m...

This work presents a novel shoal-bias, label-based generalization algorithm that utilizes the physical dimensions of the symbolized depth values on charts to avoid the over-plot of depth labels at scale. Additionally, validation tests based on cartographic constraints for nautical charting are implemented to compare the results of the proposed algo...

Safety of navigation is essential for the global economy as maritime trade accounts for more than 80% of international trade. Carrying goods by ship is economically and environmentally efficient, however, a maritime accident can cause harm to the environment and local economies. To ensure safe passage, mariners tend to use already familiar routes a...

Lightning talk presentation for the US Hydro 2021 online conference

The S-57 Category of Zone of Confidence (CATZOC) symbology with star glyphs has received much criticism for its effectiveness in maritime navigation. It adds significant clutter on Electronic Chart Displays and Information System (ECDIS) screens, obscures high-quality more than low-quality data, may not be visible in small areas, is not intuitive,...

Passage planning and monitoring are two essential and mentally demanding tasks in maritime navigation. Ships are facing higher risk of running aground when they take a route for the first time or are to stray from their planned route, and of collision when navigating areas of increased maritime traffic. Many researchers have studied methods to crea...

Ocean mapping professionals are facing challenges in various areas of the hydrographic workflow. Understanding them can be difficult, as they are many and varied, but essential toward solving them. Some understanding can be reached with studying existing specifications and reports, however a more in-depth knowledge may be acquired directly from pro...

This work presents a bathymetric data generalization algorithm based on depth labels rendered at scale. It aims to facilitate the final cartographic sounding selection for chart portrayal through the process referred to as hydrographic sounding selection. Currently, automated algorithms for hydrographic soundings selection rely on radius-and grid-b...

The hydrospatial community has advanced the use of Free and Open-Source Software (FOSS) in the ocean mapping workflow by developing new solutions and adopting tools originally developed for other applications. These specialized tools allow users to conduct common tasks in hydrography without the need for commercial software, but, most importantly,...

Bathymetric data collection in hydrographic and marine geophysical surveys is mostly achieved by utilizing vessel-mounted multibeam echo sounders (MBES), resulting in Digital Terrain Models (DTMs) of the seafloor and derived products. Previous knowledge of the seafloor depth and existing features is essential for surveyors to effectively design a s...

A brief presentation of data quality and autonomous ship navigation related projects at the Center for Coastal and Ocean Mapping, University of New Hampshire.

This is the presentation of the research "CHARACTERIZING FREE AND OPEN SOURCE SOFTWARE IN OCEAN MAPPING" for the 6th Hydrographic Engineering Conference (3 NOV 2020, Lisbon)

Over the last years, scientists and professionals have made available several free and open-source software tools meant for geophysical survey planning, underwater remote sensing data processing, and geospatial data visualization. However, the use of these tools is limited within hydrographic offices. One of the reasons could be the lack of awarene...

Depth areas are utilized by the Electronic Chart Display and Information Systems (ECDIS) along with the vessel's characteristics (e.g., draft, squat) and other situational information (e.g., tides) for separating safe areas from those unsafe to navigate. Any error in their compilation is carried over to the analysis performed in the ECDIS. As a res...

Navigational charts contain a combination of geospatial information of varying quality collected at different times using various techniques. Bathymetric data quality is mainly encoded in electronic charts with the Category of Zones of Confidence (CATZOC). CATZOC provides information about the horizontal and vertical uncertainty of depth informatio...

Charted bathymetry encompasses the cartographer's effort to accurately describe submarine topography based on the source information. A key factor in the selection process is that, at any location, the charted features do not give a false impression that the water depth is deeper than it actually is. Our research work focused on development of an a...

The Electronic Navigational Chart (ENC) consists of point, line, and area features compiled following the node-chain topological model. To ensure that the topological structure is valid, the International Hydrographic Organization (IHO) has developed a number of checks defined in Publication S-58. Many of the checks deal with the vertical component...

Data quality is visualized in ECDIS as an additional layer with symbols using a rating system of stars: six to two stars for the best to lowest quality data and “U” for unassessed data. This work presents an alternative methodology for consideration by the IHO Data Quality Working Group members.

Presentation of an improved method for the visualization of zones of confidence (ZOC) and quality of bathymetric data (QoBD) on ECDIS.

Most navigational charts are an amalgamation of geospatial information of varying quality collected using different techniques at different times. Data collected with high resolution multi-beam echo sounders or lidar systems may co-exist on the chart with data collected with lead-line as far back as the 18th century. Data quality on charts is curre...

This work addresses the 3D character of marine spaces and proposes the application of the Land Administration Domain Model (LADM conceptual standard ISO 19152) to specific jurisdictional MAS or MC, taking into account the S-121 Maritime Limits and Boundaries (MLB) Standard, which refers to LADM. Several modifications are proposed, including e.g., t...

The compilation of nautical charts comprises a number of tasks that are often monotonous, time consuming, and, as such, prone to human error. A long-term goal of the hydrographic community has thus been the automation of the process due to the unquestionable advantages of automation to the accuracy, reliability, and consistency of products for a re...

The nautical chart is one of the fundamental tools in navigation used by mariners to plan and safely execute voyages. Its compilation follows strict cartographic constraints with the most prominent being that of the safety. Thereby, the cartographer is called to make the selection of the bathymetric information for portrayal on charts in a way that...

Depth curves and charted soundings are two structural components of nautical charts, both derived from a more detailed dataset through generalization. Once depth curves are generated, the cartographer makes a selection of soundings that complements the depth curves and other features carrying bathymetric information in the adequate representation o...

The rising trend in automation is constantly pushing the hydrographic field toward the exploration and the adoption of more effective approaches for each step of the ping-to-public workflow. However, the large amount of data collected by modern acquisition systems - especially when paired with the force multiplier factor provided by autonomous vess...

Timely and accurate identification of change detection for areas depicted on nautical charts constitutes a key task for marine cartographic agencies in supporting maritime safety. Such a task is usually achieved through manual or semi-automated processes, based on best practices developed over the years requiring a substantial level of human commit...

Timely and accurate identification of change detection for areas depicted on nautical charts constitutes a key task for marine cartographic agencies in supporting maritime safety. Such a task is usually achieved through manual or semi-automated processes, based on best practices developed over the years requiring a substantial level of human commit...

Timely and accurate identification of change detection for areas depicted on nautical charts constitutes a key task for marine cartographic agencies in supporting maritime safety. Such a task is usually achieved through manual or semi-automated processes, based on best practices developed over the years requiring a substantial level of human commit...

The selection of soundings to be shown on nautical charts is one of the most important and complicated tasks in nautical cartography. From the vast number of source soundings the cartographer is called to select all those important for the safety of navigation and to verify the “shoal biased” pattern of selection against the source soundings. A lon...

The delimitation of maritime zones and boundaries foreseen by the United Nations Convention on the Law of the Sea (UNCLOS) is a factor of economic growth, effective management of the coastal and ocean environment and the cornerstone for maritime spatial planning. Maritime zones and boundaries form the outermost limits of coastal states and their ac...

The aim of this doctoral dissertation was to investigate and resolve cartographical issues in maritime delimitation, to determine the limitations of existing software solutions and to develop and implement a comprehensive methodology to address them in a digital environment. Its findings comprise three automated methodologies -and their implementat...

The creation of the Mercator chart has been a milestone in nautical cartography, namely the composition and production of charts aiding mariners to safely navigate their vessels. The development and propagation of digital systems in the last decades of the 20th century, was instrumental for the collection and processing of data pertaining to the co...

A huge immigration crisis has been unfolding in the Mediterranean region in recent years, forcing the countries involved to draw up agreements and take measures for the reception and prevention of immigration flows in the area. The study of information from the past decade shows that cooperation agreements among the states concerned contribute to t...

The interests, responsibilities and opportunities of states to provide infrastructure and resource management are not limited to their land territory but extend to marine areas as well. So far, although the theoretical structure of a Marine Administration System (MAS) is based on the management needs of the various countries, the marine terms have...

The graphic presents the result of the automatic delimitation of maritime limits and boundaries for a fictitious area.

The graphic presents the result of the automatic delimitation of maritime limits and boundaries for a fictitious area.

This paper is concerned with the delineation and delimitation methodologies proposed by cartographers and applied by States and juridical bodies. It aims to contribute to the relevant literature by providing detailed guidelines on how to construct the outer limits graphically.