Estudios de poblamiento y procesos de colonización en la zona

Hazards to navigation and identifying class definitions are based on examples likely to occur in the Arctic and the tropics, but are also commonly found worldwide. These are obtained from the United States Code of Federal Regulations (33CFR64)where three specific hazard attributes are identified as follows:

• Hazard to Navigation means an obstruction, usually sunken, that presents sufficient danger to navigation so as to require expeditious, affirmative action such as marking, removal, or redefinition of a designated waterway to provide for navigational safety.

• Obstruction means anything that restricts, endangers, or interferes with navigation.

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• Structures mean any fixed or floating obstruction, intentionally placed in the water, which may interfere with or restrict marine navigation.

Specific examples of hazards to navigation were identified by examining navigation charts from those portions of the Arctic where detailed surveys have been conducted, followed by tropical coral reef regions, and then other regions where such hazards, obstructions and structures exist. This examination also covers Notices to Mariners where hazards to navigation have been identified but are not yet charted. Attempts were also made to identify specific examples that provide realistic test cases that replicate hazard to navigation attributes and characteristics during actual in-water testing using 3D-FLS. This includes objects and features that are attached to and project from the bottom such as shoals, rocks, ledges, reefs and wrecks. Also included are test cases that represent in-water hazards within the water column, the presence of which is opportunistic in nature and not necessarily abundant or easily found in the natural environment. Similar targets such as buoys were used when available and appropriate. Differences in precision and accuracy are considered between hazards to navigation attached to the bottom and those drifting within the water column. This is anticipated due to potential differences in resolving targets that lie on a plane where adjoining hydrophone signals may tend to promote averaging of measurements, as opposed to detecting and characterizing a target that exists in free space without reference to adjoining hydrophone signals. Bottom targets are detectable with 3-dimensional characteristics, while depth information for hazards to navigation drifting in the water column may not be readily discerned.

The detection of hazards to navigation is accomplished in real time by the FarSounder system itself directly from the sonar data, eliminating any possible delay that may be incurred as a result of post-processing sonar data. The EchoPilot system has no specific capability for this purpose and detection is dependent upon user interpretation of sonar data presented in the visual display. Post processing of the raster data provided by this system would be required to detect hazards to navigation, which is beyond the scope of

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this research. Presentation on navigation displays in a form that is easily interpreted considering human factors is discussed under Study Area 5.

The process used in acquiring 3D-FLS data, analyzing the data to detect hazards to navigation, developing ENC and then displaying ENC data on ECDIS is illustrated in Figure 4.1. High resolution data representing a 3-dimensional topological model of the sea floor in areas where the bottom rises to above 50 or 100 meters, depending on make and model of 3D-FLS, is acquired live and displayed to the watchstander on ECDIS in real time while a vessel is making way. Hazards to navigation that are present either attached to the sea floor or suspended in the water column between the surface and the sea floor are detected and also displayed as momentary Virtual AtoN using appropriate symbology in accordance with existing ECDIS protocols, with minor variation to depict the virtual nature of the notification.

Static Virtual AtoN Dynamic Virtual AtoN

3D-FLS Real Time Survey Ahead of

the Vessel ECDIS

Bottom Contours Hazards to Navigation

ENC

Transient Virtual AtoN

Chartmaking Authority Aids to Navigation Authority Hydrography Hazards to Navigation Navigation Chart High Resolution 3D-FLS Data

Figure 4.1: Correlation of 3D-FLS data flow with national authorities and Virtual AtoN creation for electronic navigation chart development and display to mariners on ECDIS.

This data is also recorded and subsequently transmitted for use by national hydrographic authority in chart making, and also by national AtoN authority for determining the placement of AtoN, including static and dynamic Virtual AtoN for

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inclusion in navigation charts. This information is embodied within an ENC for display to mariners on ECDIS.

The methodology used in this research is illustrated in figure 4.2. The objectives to be achieved are defined and boundary conditions and constraints identified as the first step in our analysis. Once completed, the assessment of risk can then be performed. This is accomplished by first identifying potential hazards and development of a scenario by which their causes and consequences may be examined, followed by the identification of options to control risks and to compare benefits of each of the options. Finally, recommendations are provided based upon the hazards identified, the options to reduce or eliminate their occurrence, or the consequences and associated costs and benefits.

Figure 4.2: Risk assessment methodology

The objective of this research is to identify the various factors and reduce associated risks that may lead to the unintentional grounding of vessels, especially in remote regions where hydrographic surveys to modern standards are rare and navigation charts are incomplete and inaccurate. Also included in this objective is allision with objects that exist either afloat or present in the water column that may cause an accident. A further objective is to examine new sensor technologies and reduce the occurrence of unintentional groundings and how this may be accomplished. This includes results

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obtained directly through new technology use along with products and capabilities obtained indirectly through the post-processing and secondary use of data. Examples of new technologies include 3D-FLS and Virtual AtoN that do not require the use of AIS radio technology or physical infrastructure of any kind for its use.

This analysis is limited to SOLAS vessels that are likely to operate in the Arctic including those involved in community re-supply, bulk cargo transportation, fishing activities and tourism. Scope is also limited specifically to spatial and geographical uncertainties along transit routes that may lead to unintentional grounding.

Ship systems include those generally considered under the e-Navigation umbrella and communication systems needed for provisioning of meteorological and oceanographic data associated with weather, tides, currents and waves (sea state). This includes ECDIS, AIS, GNSS, Radar, Sonar and communications system components providing maritime safety information broadcasts. Also considered is hydrographic data for creating navigation charts, including ENC, in their present form and also with detailed hydrography data integrated within the International Hydrographic Organization (IHO) S-100 framework standard Universal Hydrographic Data Model. Specific reference is made to the draft S-102 High Definition Gridded Bathymetry standard that supports development of new navigation products not possible under the S-57 and previous hydrographic standards (IHO S-102). New products can include tools for navigation by georeferencing to known features that exist on the bottom to supplement positioning information provided by GNSS and AIS. This same hydrographic data is used for the design, implementation, placement and verification of AtoN in the Arctic to guide vessels along their routes (Wright and Baldauf, 2015 and 2015a).

Limitations include risk to personnel, environmental and property damage. A prototype case is developed to illustrate the factors involved to generalize to other segments of the Arctic fleet. Choice of route illustrates a typical trade for the vessel type and size. There is 100% ENC coverage for this route and ECDIS availability is assumed. However, ENC data content in terms of soundings and other data useful for navigation over many portions of this route is sparse and even non-existent in many

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areas. Paper charts for these areas are not required when electronic charts are in use, and high speed vessels are not considered.

A generic model characterized by functions and capabilities inherent to ship navigation was defined representing an integrated collection of systems, including the interactions of functions and systems appropriate to unintended grounding.