Three weeks ago was hold an OGC meeting in Stuttgart (Germany).
Consolidated slides giving only the main points of each presentation is
available at [1]. Below are a few elements that I noted. As usual this
is only my understanding and may contain mistakes/approximations:
New working groups being formed:
* Pipeline working group
* Statistical working group
* Blockchain and distributed ledger technologies working group
* Aviation (actually reviving a dormant working group)
* GeoAI (Artificial Intelligence) working group
The Pipeline Working Group is proposed by the the oil and gas industry.
In this environment of highly volatile products under high pressure in
underground infrastructures difficult to access, their requirements on
international standards prefer rigidity over flexibility. This reminded
me Tim Boudreau's blog "Maven's inflexibility is its best feature" (from
the point of view of an IDE).
The Statistical Domain Working Group will work on integration of
statistics and geospatial, use of metadata to link them,
disclosure/privacy issues, etc. On artificial intelligence (AI), an ISO
Technical Committee has been created in 2017: ISO/IEC JTC1 SC42, with
their first meeting in April 18 in Beijing (China). The OGC GeoAI
working group plans to coordinate their work with this ISO TC. IEEE is
launching an initiative for ethical considerations in AI.
New programmatic elements:
The Coordinate Reference Systems (CRS) working group made a report on
their new features: dynamic datum, three-dimensional projected CRS,
geoid-based vertical CRS, triaxal ellipsoids for planetary applications,
etc. Those new features are not yet implemented in Apache SIS, while I
still hope to do that somewhere in 2019. The Moving Features Working
Group published a corrigenda introducing new elements -
MovingFeatureType and DynamicAttributeType - which fill a hole in
current editions of ISO standards on which GeoAPI interfaces are based.
This element has been used for completing the org.opengis.feature Java
package in GeoAPI. Not yet implemented in Apache SIS neither, but on the
radar.
The GeoAPI working group took a look on the new C++ API of the PROJ
library, created as part of the "gdalbarn" crow-founding. The C++ API is
inspired by GeoAPI and follows closely ISO 19111:2018 model. It seems
close to what could be a "GeoAPI in C++" API. Other elements briefly
shown in the meeting was the tentative Python API (in addition of
current Java API) and the specification draft [2] (still work in progress).
For drawing symbols on a map, we did not had formal definition of
programmatic elements that we could use in GeoAPI. The closest thing
that we had was XML schema of symbology encoding. OGC is now preparing a
Symbology Conceptual Model. The core part is available in draft stage at
[3] and seems better suited to GeoAPI.
New format, service or registry:
The GeoPackage format may be extended to include "Common Data Base"
(CDB) vector data - a synthetic environment database for storing
computer simulation that represents activities at a high level of
realism. CDB were previously using Shapefiles. The move to GeoPackage
would allow to reduce the number of files and disk usage.
The Web Feature Service (WFS) 3.0 draft is available at [4]. The first
release (tentatively next year) will not cover all WFS 2.0
functionalities. WFS 2 and WFS 3 are expected to exist in parallel for
some time. Since WFS is also an ISO standard, WFS 3 will use a new ISO
number for avoiding to discard WFS 2.
There is a need to allow other authorities (e.g Astronomical Union,
Oceanographers) to register new Coordinate Reference Systems (CRS), e.g.
for depth axes measured by pressure. We have not yet clarified what
would be the process for submitting new CRS to OGC. This is a recurring
demand.
The concept of DataCube became popular recently, especially in the
context of Earth Observation. A DataCube can be understood as a
specialization of the Coverage structure defined by ISO 19123 in the
special case where data are gridded. The number of dimensions can be
anything, and DataCubes shall support efficient trimming and slicing.
Actually this is not really new. As far as Apache SIS is concerned for
example, there is nothing to change; it is already in-line with the
requirements enumerated at OGC. Those requirements are:
* Shall support gridded data of between two to four spatial-temporal
dimensions.
* Uses the Geographic Coverage model as defined in OGC Coverage
Implementation Schema (CIS).
* Shall prepare and structure raw observation data to support analysis
with minimal additional preparation when analysis is requested.
* Shall provide metadata for the user that defines the provenance of
all source data, data preparation methods and structure.
* Shall support analytics on all domain axes alike, irrespective of
the axis spatial or temporal semantics.
* Shall allow efficient trimming and slicing along any number of axes
from a datacube in a single request.
* Shall allow tuning of performance to anticipated user query patterns.
* Shall provide server-side analytic processing on the data including
composite extraction, processing, filtering, and fusion tasks in
ad-hoc fashion.
* Shall support access to metadata.
Other new stuffs:
In addition of standards, OGC was used to publish "Best practice"
documents which are not standards but describe some recommended uses of
standards. This category of document has been refined in two categories:
"Best practice" (as before) and "Community practice". The main
difference is that "Community practice" describe the use of de-factor
standards that originated outside OGC.
The OGC Naming Authority is defining identifiers in the
http://www.opengis.net namespace. But this namespace is only for
formerly approved OGC resources. For resources under development, a new
namespace has been defined: http://dev.opengis.net.
A data quality vocabulary is being developed at W3C [5]. It is not a
standard yet.
Tests
Current beta version of CITE tests cover the following:
* CSW 2.0.2 (current version: 1.18)
* GeoPackage 1.0 (current version: 1.1)
* GeoPackage 1.2 (current version: 0.7)
* SensorThings API 1.0 (current version: 1.2)
* WFS 2.0 (current version: 1.30)
* WMS 1.1 (current version: 1.18)
* SWE Common 2.0 (current version: 0.3)
* WMTS 1.0 NSG Profile (current version: 0.3)
* GeoPackage 1.2 NSG Profile (current version: 0.5)
* WMS 1.3 NSG Profile (current version: 0.2)
[1] https://portal.opengeospatial.org/files/?artifact_id=81129
[2] http://www.geoapi.org/snapshot/standard_document.html
[3] https://portal.opengeospatial.org/files/?artifact_id=80686&version=1
[4] https://cdn.rawgit.com/opengeospatial/WFS_FES/3.0.0-draft.1/docs/17-069.html
[5] https://www.w3.org/TR/vocab-dqv/
Martin
