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Some of the terms listed below are specific to xviewsdts.  Some are specific to SDTS.  Some are used by both.  When definitions are given for SDTS terms, the definition applies to the term only as used by xviewsdts.  (For instance, definition 2 given here for CATD says that CATD is the name of the catalog/directory module; this is true in the xviewsdts world, which currently uses only the Topological Vector Profile, but may not be true for other profiles which are not used by xviewsdts.)

Brief definitions given here are sometimes followed in smaller print by quotations from the appropriate SDTS document.  These definitions are here for convenience, but should not be considered a substitute for the original documents.  For the best definition, consult the latest versions of those documents.


 

ATID

Mnemonic for the Attribute ID, which is a module field containing an integer indicating the Record ID within an Attribute Primary module.

In the SDTS Logical Specifications, the description of the Attribute ID is defined for each transfer module record type.  For many modules it is described simply as the "Foreign identifier for Attribute Primary module Record."
 

CATD

1.  Mnemonic for Catalog/Directory, which is a field in the catalog/directory module.

SDTS, Part 1, Section 5.2.2.1 says, "This module contains information on where to locate all modules within the transfer."

2.  Name of the catalog/directory module

SDTS, Part 4, Section 4.1 says, "Non-object modules shall be named the same as the primary module field mnemonic."

3.  Field in the What's This description boxes used for the pathname of the catalog/directory module's file.

See What's This: Show IDs.
 

ENID

Mnemonic for Endnode ID, which is a field in the line module containing an integer indicating the identity of the record within the point-node module for the point-node at the end of the line.

In the SDTS Logical Specifications, the End Node ID is described as "Foreign identifier of end node Point-Node module record."
 

Module

A group of SDTS records commonly (but not necessarily) contained in a single file.

Or, from the SDTS Logical Specifications:

1.5.20  Module - A logical collection of module records.
1.5.21  Module field - A defined set of one or more module subfields in a Spatial Data Transfer.
1.5.22  Module record - A defined set of one or more module fields in a Spatial Data Transfer.
1.5.23  Module specification - The meaning, identification, order requirements, and data structure requirements for data belonging to the module.
1.5.24  Module subfield - A logical construct defining a single data element in a Spatial Data Transfer.

 

RCID

Mnemonic for Record ID, which is a module subfield containing an integer indicating the identity of the record within a given module.

In the SDTS Logical Specifications, the description of the Record ID is defined for each transfer module record type.  For instance it is described as the "Line object record identifier" for the line module specification, and as the "Polygon object record identifier" for the polygon module specification.  But for many modules it is described simply as "a number for the module record, unique within the module," which is a useful overall description.
 

SNID

Mnemonic for Startnode ID, which is a field in the line module containing an integer indicating the identity of the record within the point-node module for the point-node at the start of the line.

In the SDTS Logical Specifications, the Start Node ID is described as "Foreign identifier of start node Point-Node module record."
 
 

Theme

A subset of the surface data containing objects of a similar nature.  For instance, xviewsdts currently supports the following themes:
Boundaries
Hydrography
Roads & Trails
Railroads
Miscellaneous Transportation
Or, from the SDTS Logical Specifications:
1.5.36  Theme - A generalization of entity classes (e.g., culture, hydrography, transportation).

 

Vertical Relation

An attribute describing the relationship between two features where one passes over or passes under another, as in the case of a bridge.

Or, from the DLG3 Master Data Dictionary / Definition file:

This attribute describes the vertical relationship of a feature to another feature.  Examples are features which overpass or underpass other features.


Copyright © 2002 by Dapper Mapper

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