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XMML Summary


Introduction

XMML, the eXploration and Mining Markup Language, is an XML based encoding for geoscience and exploration information. It is intended to support exchange of exploration information in a wide variety of contexts. This includes exchange
  • between software packages on the desktop,
  • between users and organisations,
and must be compatible with http.

Since XML is a plain-text format within which the tags provide a degree of internal documentation, it is highly suitable for archival use (transfer across time ...). Software required to interpret XML documents at a basic level will be more reliably available many times longer than the (versions of) application software required for most proprietary formats. Furthermore, the GML idiom used by XMML ensures that a certain amount of "schema-level" information is present in the data instance (all objects are clearly labelled with their data-type, as well as their role in context) which reinforces this portability.

XMML has been designed on the premise that exploration data is essentially geospatial, so there are benefits in using an implementation framework that is aligned with other geospatial information systems.

The XMML implementation is based on Geography Markup Language (GML), developed by Open GIS Consortium (OGC) and currently undergoing standardisation as ISO 19136. By choosing this basis the following are obtained:
  1. a basic meta-model, based on features, properties, objects and values
  2. a regular XML encoding pattern used to serialise instances conforming to the meta-model
  3. inheritance of a large number of utility components, particularly concerning geometry, topology, temporal, coordinate reference systems, which therefore do not have to be re-invented
  4. conformance with standards from the ISO 19100 series
  5. compatibility with the OGC Web Feature Service (WFS) interface
  6. potential for integration with data expressed in other GML-based languages
  7. compatibility with national Spatial Data Infrastructures
  8. widespread availability of basic processing tools and software components, particularly for transformation to legacy formats, and styling for portrayal and reports.

XMML itself will be standardised through the IUGS Commission on Geoscience Information. The XMML code is freely available from the website http://www.seegrid.csiro.au/xmml.

Development Methodology

The development of XMML is sponsored by a number of mining and service companies and agencies (see ProjectSponsors and acknowledgement at the foot of this page). Priorities are determined through sponsor requests and feedback. The requirements for specific feature types have been primarily based on existing models supplied by the sponsors, often as implied by file format definitions and illustrated by sample instances.

The design process involved iterating between prototype XML instances and WXS schemas. The instances were inspected to ensure that the information content was complete relative to the supplied samples, and also distributed to the interested sponsors for feedback. The schemas were required to
  1. effectively validate the sample instances
  2. be suitably modularised, so that
    • useful generalisation and specialisation relationships were captured
    • components common to several feature types were effectively factored out and re-used

As an additional test of the integrity and consistency of the models, most have been converted to UML class diagrams, following the methodology described in the GML 3.1 specification.

Further development of XMML is being pursued in collaboration with the SEEGrid initiative, the AEON network, and the IUGS/CGI Working Group on Data Model Collaboration.

Catalogue of XMML feature types

For the release of Version 1 of XMML, the feature types of primary interest are:
  • Borehole with logs
  • Geochemistry result (Assay data and Statutory reporting data)
  • Geological Timescale
  • Geometry features based on Points, Curves, Surfaces and Solids, extensions with basic properties, and extensions suitable for map-features
  • Geological boundaries of various types
  • Mineral occurence
  • Observation, Gravity Measurement

Many other XML elements are declared in the XMML schema with "global" scope. While these are mostly "support" elements, used in the context of one of the primary feature types, they may be used as the root element in a document when required. In particular the following are provided:
  • Coverage, Pointset coverage, Interval coverage, Curve coverage, TIN coverage, Rectified Grid coverage
  • Project, Specimen, Station, Tenement, Material
In addition, a number of components and feature types have been developed to support numerical modelling (finite elements, plate rotations).

Note that the feature types here are dominantly observations and artefacts, rather than geological objects, which are necessarily the results of interpretation.

Deployment

Specific software may be XMML-enabled natively. Applications from Fractal Technologies, CSIRO, Metech/Acquire and ALS-Chemex have taken this route. Use of a rich but neutral, non-proprietary format like XMML for information exchange may, in time, diminish the need for software vendors to implement multiple proprietary import/export options.

Standard XSLT technology can be used to build stand-alone filters to convert XMML instances to legacy formats, or for presentation and display. Examples of these are provided on the website.

Data Grid

XMML is primarily designed to contribute to a geoscience community language, as part of a Geoscience Grid in the context of standard Spatial Data Infrastructures. The vision is a deployment of data, processing and computational nodes as web-services. Providing the service interfaces are standardised, they may be connected at run-time into loosely-coupled service chains.

The necessary standardisation includes
  1. the request/response protocol - the basic protocol for delivery of feature data in GML is WFS, which is supported by a number of COTS and Open Source applications.
  2. the information model and encoding for the payload - XMML and related geoscience languages.

Note that this deployment model puts the burden of mapping from the private model to the community model (XMML) onto data-providers. The assumption is that it is more efficient for information to be presented to users in a standard form, than to require them to understand and convert from many models.


The XMML project acknowledges the generous financial support provided by Fractal Technologies, CSIRO, MERIWA, WMC, Snowdens, Placer Dome, GA, BGS, GGIPAC and Metech.
Topic revision: r6 - 15 Oct 2010, UnknownUser
 

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