EDCS Reference Manual
Environmental Data Coding Specification (EDCS)
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 or other DRM 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 must result in a shared understanding
of "what the thing is and what it potentially means" to all
applications consuming that transmittal.
For more detailed information on the EDCS, visit the following pages: