Nautical data models

Nautical Solution provides data models for the transfer, conversion, and production of hydrographic data to be used in ArcGIS. A data model is a database schema that allows the organization of all data types in the geodatabase.

Features

A feature is a representation of a real-world object on a chart, such as points, lines, and polygons. Nautical features are based on S-57 spatial and feature objects.

S-57 spatial objects are commonly referred to as vectors or primitives in the geodatabase. S-57 feature objects are commonly referred to as features and are divided into four types:

• Meta—Contains information about other objects (M_COVR, M_NSYS, M-NPUB, and so on). The S-57 meta feature objects are within the MetaDataA, MetaDataL, and MetaDataP feature classes.
• Geo—Carries the descriptive characteristics/attributes of a real-world entity (DEPARE, LNDARE, BCNCAR, SOUNDG, and so on).
• Collection—Feature object that describes the relationship between other objects (C_AGGR, C_ASSO).
• Cartographic—Contains information about the cartographic representation of real-world entities.

Subtypes

The S-57 feature objects are expressed as subtypes that are grouped into feature classes or tables based on shared S-57 attributes and Chart 1 categories. For example, the S-57 feature object representing a cable area (CBLARE) is stored in the geodatabase as a subtype named CBLARE within the OffshoreInstallationsA feature class in the Nautical feature dataset. You can find which feature class an S-57 object is related to by searching the S-57 Object Finder. A geodatabase that uses subtypes performs better, especially within an enterprise production environment with multiple users.

Feature classes

Feature classes are a collection of geographic features with the same geometry type (such as point, line, or polygon), the same attributes, and the same spatial reference. Feature classes in the Nautical Solution are organized based on S-57 objects that share attribute fields and are grouped in a manner similar to U.S. Chart 1 categories (for example, C—Natural Features).

PLTS_VectorConnectedNodes, PLTS_VectorEdges, and PLTS_VectorIsolatedNodes are three primitive feature classes (within the Nautical feature dataset) that store S-57 spatial objects (vectors or primitives). The Nautical_Topology feature class is also included in the Nautical feature dataset and is configured with topology rules related to S-57 data, which are defined from some of the spatial S-58 validation rules.

The Nautical Solution also includes other feature classes organized in other feature datasets and stand-alone support feature classes. The stand-alone feature classes are

1. ClosingLinesL—Contains features that are used to close off certain areas (between LNDARE and DEPCNT lines) and are used by the Generate Depth Area geoprocessing tool
2. PLTS_NAUTICAL_DELETES_A—Stores area features that have been deleted with the Track Deletes tool, along with the reason for deletion, editor name, and the date the feature was marked for deletion
3. PLTS_NAUTICAL_DELETES_L—Stores line features that have been deleted with the Track Deletes tool, along with the reason for deletion, editor name, and the date the feature was marked for deletion
4. PLTS_NAUTICAL_DELETES_P—Stores polygon features that have been deleted with the Track Deletes tool, along with the reason for deletion, editor name, and the date the feature was marked for deletion

Feature datasets

A feature dataset is a collection of related feature classes that share a coordinate system. The feature datasets provided with the Nautical Solution are

• Nautical feature dataset—Stores all the S-57 feature and spatial objects and uses a geographic coordinate system based on the WGS 1984 datum
• CartographicFeatures feature dataset—Stores light sector lines and is used to store data related to source diagrams
• GRD_Grids feature dataset—Stores all grid components (annotation, points, endpoints, ticks, segments, clipping polygons, and neatlines)
• Masks feature dataset—Stores polygon masks and relationship classes between nautical feature classes and mask feature classes

Tables

Nautical support tables are used for a variety of functions, and they all support the production of S-57 datasets:

• PLTS_COLLECTIONS—Stores a record for all existing collection objects
• PLTS_DSPM—Stores dataset parameters (vertical/sounding datum, compilation scale, measurement units, coordinate multiplication factor, and so on)
• PLTS_EXPORTS—Records exports and publication of product cells
• PLTS_FREL—Stores S-57 feature relationships (master, slave, and collections)
• PLTS_MASTER_SLAVES—Sets list of potential master and slave features derived from ENC and AML product specifications
• PLTS_NAME—Stores long name (LNAM) and NAME parameters to be used for new feature creation
• PLTS_PRODUCT—Product identification (ENC, AML profile type, Charting)
• PLTS_SREL—Records spatial relationships between features and their related primitives

Data models

The nautical models included in the Nautical Solution are for hydrographic data storage of the following:

• Nautical Information System (NIS)
• Electronic Navigational Chart (ENC)
• Nautical Chart (Hard-copy Chart Specifications of the IHO M-4-Chart 1)
• Additional Military Layers (AML)
• Digital Nautical Chart (DNC)

NIS

The NIS geodatabase model is used in the enterprise implementation of the Nautical Solution and is designed to store large hydrographic datasets of overlapping scale bands. S-57 products of all types can be stored in the NIS data model. The NIS geodatabase model uses the Nautical feature dataset (without the Nautical_Topology feature class), stand-alone support feature classes, and the support tables. The image below shows how the NIS data model is organized.

ENC

The ENC data model supports six scales: Berthing, Harbor, Approach, Coastal, General, and Overview. All S-57 objects are available in all six scales; therefore, there is only one ENC data model. The ENC data model is used in both the enterprise and desktop implementations. The ENC data model contains the Nautical feature dataset, stand-alone support feature classes, and support tables. The image below shows how the ENC data model is organized.

Nautical Chart

The Charting data model supports hard-copy and raster nautical chart production at any scale, in both the enterprise and desktop production environments. It stores S-57 feature objects as well as cartographic information. The Charting data model contains the CartographicFeatures, GRD_Grids, Masks, and Nautical feature datasets, as well as the stand-alone support feature classes and support tables. The image below shows how the Chart data model is organized.

AML

The six AML profiles supported by the Nautical Solution have individual data models for each. The AML data models included are

• Contour Line Bathymetry (CLB)
• Environment, Seabed, and Beach (ESB)
• Large Bottom Objects (LBO)
• Maritime Foundation and Facilities (MFF)
• Routes, Areas, and Limits (RAL)
• Small Bottom Objects (SBO)

The AML products are currently only configured for the desktop production environment (no central data repository). The AML digital transfer standard is based on the internationally accepted S-57 transfer standard for digital hydrographic data. The AML models include the Nautical feature dataset, stand-alone support feature classes, and support tables. The image below shows how the AML data model is organized.

DNC

There are four DNC data models which support each of the four DNC scales: Harbor, Approach, Coastal, and General. The DNC data models are only supported in a desktop production environment (not in enterprise SDE). The DNC data models contain the DNC feature dataset for each scale (for example, DNCH for Harbor scale, DNCA for Approach scale, and so forth), geodatabase topology, and support tables.

DNC production is supported in a desktop production environment with four scale-specific geodatabase models: Harbor (DNCH), Approach (DNCA), Coastal (DNCC), and General (DNCG). You choose the appropriate scale for the production of each DNC library (Harbor, Approach, Coastal, or General). The DNC models contain specific DNC feature datasets and some support tables. DNC feature datasets consist of feature classes and subtypes specific to each DNC scale. For example, the DNC Harbor scale contains all DNC features, whereas with the smaller DNC scales (like General) fewer features are needed. The support tables found in the DNC models include DBS_FC_VVT and notes tables. The image below shows how the DNC data model is organized.