Hello all
Below is a summary of some points discussed at OGC's 104th Technical
Committee (TC) meeting 3 weeks ago. More than 200 people attended the
meeting, hosted by Ordnance Survey (U.K.). Some key points of each
session are consolidated in public slides there:
https://portal.opengeospatial.org/files/?artifact_id=75873
This email covers only a small part of the meeting, basically the parts
I attended. The main one was discussions around the ongoing revision on
ISO 19111, the standard defining Coordinate Reference System (CRS)
abstract model and coordinate operations (map projections, datum shifts,
/etc./): two sessions Monday, the full Tuesday (actually an ISO parallel
event) and more at lunch time the next days. We try to support tectonic
plate motions, but without bothering too much the people who do not need
this precision. We also try to address better the needs of the
meteorological community, in particular heights measured by pressure and
time positions not directly related to ISO dates. Finally we propose a
replacement for the ImageCRS type, which was not addressing the need of
the Grid Coverage community. Current replacement proposal is
EngineeringCRS associated with a new coordinate system type, OrdinalCS.
Another session was about Hierarchical Data Format (HDF), a format
defined outside OGC but proposed for standardisation in OGC. A draft on
GitHub (annex C) proposes a mapping between netCDF and HDF5 data model.
Example:
netCDF
HDF
Dataset
File
Dimension
Dataset
Variable
Dataset
Variable shape
Dataspace
Attribute
Attribute
Global attribute
Root group attribute
Another session was Moving Features. We discussed the limitations of
netCDF as a binary format for Moving Features, and the idea that HDF may
be more appropriate. Some useful HDF features are variable length
arrays, enumerations and "region references". The later allows to have
an array of time-dependent coordinates describing an object geometry and
to reference different parts of that array for different times.
Another session was netCDF. A "NetCDF Earth Observation (EO) Metadata
Conventions" (OGC 17-067) discussion paper is under preparation. This
paper defines additional attributes, beyond the ones defined by
CF-Convention, for Earth Observation. Examples include information about
Platform/Instrument/Sensor used for the acquisition, histogram,
uncertainties information, orbit, /etc./
The Simple Features session presented their plan for the next ISO/OGC
standard. This is a standard of critical importance, and the revision is
quite big. Current proposal is to split this document in 7~10 parts.
Some parts will give definition of taxonomy, ontology and schema. The
current standards are structures around schemas (XML schemas, UML or
Java interfaces). There is a demand to support schema-less languages or
formats like JSON, in which case the standard would use ontology instead.
The meeting had a focus on Smart Cities and associated topics, such as
Energy and Utilities, Land and Infrastructure, etc. One talk was from
the Association of Oil and Gas Producers (IOGP) discussing the realities
of a carbon-producing industry operating in an environment with
increasing pressure to decrease carbon output and what geospatial
capabilities would need to be leveraged by that industry.
The Geopackage 1.1 standard will be deprecated, to be replaced by
Geopackage 1.2.
Web Processing Service (WPS) API has been used for demonstrating
transactional WPS between 52North and Spacebel.
The United Nations discussed integration of geospatial and statistical
information. More information on http://www.unggrf.org/
The OGC Architecture Board (OAB) presented a review of technology trend
and security issues. One recurrent item is linked data. This topic has
become more important as a result of the recent publication of the joint
OGC-W3C Spatial Data on the Web Best Practices document:
https://www.w3.org/TR/sdw-bp/
Above is only a small fraction of the spectrum of topics discussed. For
a wider spectrum, see the link given that the beginning of this email.
Martin
