The information on this page was initially collected to serve a 'LADM and InfraGML' teleconference Feb. 28.
The information was later supplemented, but the scope is still to serve as a basis for future LADM and InfraGML teleconferences (next April 3rd), for the invited 'Land Use Policy'-paper: 'Alignment of Standards through Semantic Tools - The Case of Land Administration', and also for the below mentioned parallel revisions, specifically of LandInfra.

The draft Land Use Policy paper includes the following sections, which are commented upon below.

4. Thesaurus development:
    1. CaLAThe hosting on general semantic platform replaced by hosting at the OGC Definition Server

5. Motivating next steps:
    1. The Land Administration scope: Parallel revisions of LADM and LandInfra
    2. The cross-domain scope, including linkages to other structured, but non-geospatial data.

Content

  1. CaLAThe, the Cadastre and Land Administration Thesaurus
  2. SKOS, Simple Knowledge Organization System, which support the use of knowledge organization systems (KOS) such as thesauri, ..
  3. Code lists
  4. LandInfra/InfraGML
  5. Comparing draft LandInfra with other standards (Boulder 2015)

CaLAThe

The acronym CaLAThe refers to the Cadastre and Land Administration Thesaurus, which is available at http://cadastralvocabulary.org. The thesaurus comprises terms from both LADM and LandInfra, and is enhanced through visualization of term hierarchies, cf. the example on Land below.

CaLATheOnLand
Searching for e.g. Surveyor illustrates, how the term is qualified differently in LADM (marked with LA_) and in LandInfra (marked with LI_), and thus facilitates alignment discussions.

CaLAThe is available not only through http://cadastralvocabulary.org, but also through the Bartoc Skosmos tool. CaLAThe is presented among social science vocabularies at http://bartoc-skosmos.unibas.ch/CaLAThe/en/, thereby providing acces to controlled vocabularies outside the geospatial domain.

Finally, CaLAThe is available through the Definitions Server of the OGC at CaLAThe/4.0/. For example, the search
    https://defs.opengis.net/elda-common/ogc-def/concept?labelcontains=condominium
renders the following 11 terms, (edited to occupy less space).

CondominiumQuery
The individual concepts are further described with broader and narrower concepts, if available. Next the term Building use part is rendered:

CaLATheViewBuildingUsePart.

SKOS

CaLAThe is communicated to Bartoc and to the Definitions Server in terms of the W3C-recommendation on SKOS. CaLAThe in SKOS format is available, and may be visualized also through  http://labs.sparna.fr/skos-play/. The following example illustrates the location of the Building use part in the concept hierarchy:
(The text label is cut off; similarly, LA_LegalSpa should read: LA_LegalSpaceBuildingUnit), cf. following figure.
 
CaLATheViewCondominiumBuilding

CaLATheViewLA_LegalSpaceBuildingUnit

Code lists

The most recent version (4.0) of CaLAThe also includes code lists from parts of LandInfra, and a few of LADM. These code lists, their names and values, are best visualized through http://labs.sparna.fr/skos-play/. They are stored in the Concept scheme CaLATheCodelist, while the ordinary elements are recorded in the Concept scheme CaLAThe. SKOS Play thus offers a choice:

SKOS Play choice

namely between CaLAThe 4.0 with 249 concepts, and CaLAThe 4.0 - Code lists with 111 concepts.

CaLAThe code list 'members': Code list names and values, are also available from
https://defs.opengis.net/elda-common/ogc-def/resource?uri=https://www.opengis.net/def/CaLATheCodeList/4.0/&_format=html

LandInfra/InfraGML

OGC LandInfra/InfraGML is available from https://www.ogc.org/standards/infragml
The standards were developed during 2015-2017, reflecting the then missing update of LandXML
The cadastral part of LandInfra came in as a necessity, as infrastructure projects, roads and railways, etc, change land ownership and boundaries. Yet, the LandInfra conceptual model standard in sections 7.10 and 7.11 covers cadastral issues in terms of property units, cadastral parcels, easements and condominiums.

The InfraGML Part 7 - Land Division encoding standard includes in section B3 an example of the establishment of condominium units. The concerned .xml-file is rendered in InfraGML, but unfortunately, the corresponding .xsl-file is not included in the standard's example. However, the mentioned files are available here:
Ex1: Part7CondominiumExample
A revised version of the above Ex1 is made. The content of the xml-file is strictly validated, and a detail in the xsl-file, regarding rendering of parcel id, is corrected
Ex1A: Part7CondominiumExample2103. The .xml file is transformed to .html by means of the .xsl file CondominiumExample2103.xsl. The .xml file is validated by means of Altova XMLSpy.

Due to the infrastructure focus of LandInfra/InfraGML, it was out of scope to relate specifications to the information systems applied by the authority in charge of the cadastre. Therefore, LandInfra/InfraGML intend to specify the information sets, which articulates the intended cadastral change, as observed by the licensed surveyor. These information sets include existing property units, existing cadastral parcels, temporary parts of cadastral parcels, new/applied for cadastral parcels, and new/applied for property units. LandInfra moreover specifies the corresponding property boundaries with hedges and boundary marks, and finally the requested information on right of way or similar land-use restrictions.

Ex2: Cadastral Account Documents illustrates the information sets by means of three documents: A schematic account of cadastral changes, a coordinate list with point details, and a sort of copy of a cadastral map, showing the present and the intended state of boundaries and units. The main content of the documents (without signatures, etc) is rendered in one .xml-file, which is transformed into .html by means of the .xsl-file CadastralAccountExample0608.xsl. The information provided has to become interfaced with the national information systems, but this should be pretty simple, as information is specified according to the xml format.

Nødebo presentations, 2017

As the LandInfra standard was issued in 2016 and the InfraGML in 2017, their implementation were advocated at a QGIS user conference, August 2. – 11.  2017  in Nødebo, Denmark.
A background paper provides an introduction to the domain: QGIS for Cadastral Management.
OGC contribution towards standardisation in the Land Administration domain is reported here.

Comparing draft LandInfra with other standards (Boulder 2015)

At the outset of engagement in the LandInfra standardisation effort, I presented the following material:
                      Source: (OGC)Technical Committee* Meetings 2015 Meetings 2015 Boulder GIS-BIM Workshop [for OGC members only]


Jacynthe Pouliot et al (2019) How to quickly detect the overlap and the consistency between LADM with LandInfra and LandXML: Application of schema matching techniques referred to it and thus motivated me to make it public available in its draft form.
Erik Stubkjær, est@land.aau.dk, 2020-07-17; 04-06, -04; 03-14; 02-27