S-57 Spatial Coder

You may want to directly edit the primitive attributes of a selected feature in an S-57 production database. To do so, you must select a single S-57 feature in the data view so that the S-57 Spatial Coder tool can expose the attributes of associated primitive records. The Update tab on the Manage Features window allows you to modify a feature's positional accuracy (POSACC) and quality of position (QUAPOS) attributes on a selected primitive record but not the fields stored within the Feature to Spatial Pointer table. The S-57 Spatial Coder gives you the ability to modify not only the POSACC and QUAPOS attributes but also the MASK attribute in the Feature to Spatial Pointer table.

Spatial attributes

The S-57 standard requires geometric primitives (more commonly referred to as a feature's geometry) to have attributes. Spatial attributes for ENC and AML contain information about the POSACC and its QUAPOS. Other S-57-based products contain additional attributes. The Nautical Solution stores this information in two different ways.

The S-57 Spatial Coder tool accesses the spatial attributes that live directly on the geometric primitives. These attributes are exported to S-57 when using the Geodatabase to S-57 exporter.

You can also edit spatial attributes on the feature itself. This gives a you an alternative way to store this spatial information, which is interpreted by the Update Primitives tool when you build the geometric primitives for S-57.

Spatial attributes play an important role in how a feature is displayed in an electronic chart display and information system (ECDIS) using the S-52 Presentation Library. This is the electronic display version of a paper chart. An example of this is a dashed coastline. If the QUAPOS spatial attribute associated with the feature's primitive equals 4, it causes that section of the feature to draw as a dashed line as opposed to a solid line.

Feature record to Spatial record

The Feature to Spatial Pointer table also plays an important role in how a feature is displayed on an ECDIS using the S-52 Presentation Library. Orientation tells the system which direction the feature's symbology should be drawn. In ArcGIS, orientation is determined by the direction in which the feature was digitized. Update Primitives deciphers this information when updating the spatial information. A masking indicator is used to mask a feature's display. When a feature's masking is turned on for that geometric primitive, no symbology is displayed when viewing that feature's segment using S-52 symbology.

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You are only able to access a feature's masking attribute via the S-57 Spatial Coder tool.