Environmental Data Coding Specification (EDCS)

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In order to support the unambiguous description of environmental data, SEDRIS specifies:

  • a Data Representation Model (DRM)
  • a Spatial Reference Model (SRM), and
  • an Environmental Data Coding Specification (EDCS).

While the DRM addresses how to describe "environmental things" in terms of data modeling constructs meaningful to simulation developers (e.g., geometry, feature, image, topology, and data table), it explicitly avoids specifying "where" the "environmental things" are, and enumerating all of the "environmental things" that these data modeling constructs could be used to represent.

The SRM captures and unifies the spatial models used by SEDRIS, plus the many others that are not currently used but can be easily added. These models include inertial, quasi-inertial, geo-based, and non-geo-based (purely arbitrary Cartesian) systems. The SRM provides a unifying mechanism for specification and inclusion of any spatial reference frame and coordinate system. Its algorithms are designed to retain a high degree of accuracy during transformation and conversion operations (1mm accuracy).

The EDCS provides a mechanism to specify the environmental "things" that a particular data model construct is intended to represent. That is, a "tree" could be represented alternatively as a <Point Feature>, an <Aggregate Geometry>, a <Data Table>, a <Model>, or some combination of these and other data modeling constructs. Which of these the data modeler (i.e., the data provider of a SEDRIS transmittal) chooses is orthogonal to the semantic of the "thing" that is represented (and its location). The provision of such a "thing" in a SEDRIS transmittal pre-simulation must result in a shared understanding of "what the thing is and what it potentially means" to all participating applications.

For more detailed information on the EDCS, view the EDCS Reference Manual.


The ISO/IEC 18025 (EDCS) International Standard may be viewed on-line or downloaded for local use.

The ISO/IEC 18041-4 (EDCS Language Bindings: Part 4: C) International Standard may be viewed on-line or downloaded for local use.


The EDCS implementation components may be viewed or searched on-line, or downloaded for local use.

The current EDCS Software Development Kit (SDK) is also available for download.


  • SEDRIS Data Coding Standard (SDCS) (March 1999)
  • [ Now known as the Environmental Data Coding Specification (EDCS) ]
    Discusses how the SEDRIS Data Representation Model (DRM) relates to the SEDRIS Data Coding Standard (SDCS); why are they separate; the organizational structure of the SDCS; how the components relate to standards external to SISO (both legacy and future); the extents, capabilities and contents of the SDCS; and how the SDCS relates to the High Level Architecture (HLA) Object Model Data Dictionary (OMDD).


A tutorial on the EDCS presented at SEDRIS Technology Conference (STC) 2004 is also available for download.

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Last updated: July 1, 2011