The HDM Version 2 provides a significant improved implementation model over the original HDM Version 1 by taking advantage of:
- more up-to-date best practice principles
- related standards of ISO 19100 - Geographic Information
- Open GIS Consortium (OGC) guidelines and principles
The HDM has also taken into account the activities carry out by the data standard drafting processes within INSPIRE, ensuring there is a consistent approach to harmonise the exchange of geographic information.
INSPIRE is a European Union initiative designed to "trigger the creation of a European spatial information infrastructure that delivers to the users integrated spatial information services. These services should allow the users to identify and access spatial or geographical information from a wide range of sources, from the local level to the global level, in an inter-operable way for a variety of uses. The target users of INSPIRE include policy-makers, planners and managers at European, national and local level and the citizens and their organisations. Possible services are the visualisation of information layers, overlay of information from different sources, spatial and temporal analysis, etc."
The model implements all the original content of HDM Version 1and introduces new modules for Native Title and the ANZLIC Metadata Profile, as well as placeholders for other identified modules that may require standard models to be developed. The only exception was the Street Address module, whose development was deferred on the basis that decisions need to be made regarding the relationship between HDM and a range of candidates, including the relevant Australian Standard (AS4590), the Geocoded National Addresses (G-NAF) and an international standard.
One of the outcomes from the Native Title module was the re-design of the Cadastre package, introducing HDM Version 2 to Rights, Restrictions and Responsibilities and the engagement with the international community.
The revised model consists of two parts:
First, The Model
The model and associated files (EAP source, EAP/XMI source files and XMI 1.0) are version controlled, using the SEEGrid community subversion repository.
Second, The Schema
Schemas have been created by automated processing of the model using the latest version of the ShapeChange tools.
Note: These schemas have been checked for schema validity but have not been reviewed in detail or exercised in practice.