RE: SDW IG focus days in August

Hi Jeremy, Linda, all,

I’m about to be on leave till next Tuesday so I’ll reply on the various all IG points then.

Regarding “Currently this work doesn't appear to be pushed to the GH-Pages branch. It would be worth cleaning up old branches that aren't required anymore :-)” – happy to look at clearing up old branches but the implementation reports were pushed to GH-pages at end of July - :)


From: Jeremy Tandy <>
Sent: 07 August 2018 15:24
To: George Percivall <>; Linda van den Brink <>;
Subject: SDW IG focus days in August

Hi all - it’s focus days time, so Linda and I have tried to be focused too. We’ve spent a fair chunk of today looking at where we are with the various activities for SDW and tasking a look ahead to what is coming up - including OGC TC (Stuttgart) and W3C TPAC (Lyon)

George - there are specific questions for you around the OGC Tech Trends teleconference scheduled for next week (14-Aug).

We’ve identified some things for the group to focus on during this week - search for “Focus” further down in the email :-)

Jeremy and Linda.

Our agenda:
1)     IG progress and workings
2)     The scheduled call w George P to review OGC Tech Trends
3)     Progress around CityGML / CityJSON
4)     OGC TC Stuttgart
5)     TPAC planning


1/  IG progress and workings

Retrospective from July:


Pull Requests: nothing outstanding

Can we improve the working practices for the SDW IG?
                - The IG isn't really focused on delivering a "thing" - like the SDW WG was; we have a number of related, but largely independent, activities that are being shepherded by the IG.As a result, things feel quite fragmented.
                - Currently, we're not using Gitter. Would this help during focus days (or other times) - or is it a distraction?
                - Jeremy and Linda could do a better job of notifying the IG about the upcoming focus days BEFORE they happen; suggest we plan a month ahead and agree the dates for next month when we wrap up a set of focus days. Put these dates in the "meetings" Calendar.
                - Retrospective for focus days seems quite helpful keeping each of the activities focused on what we've agreed to do.
                - It's northern hemisphere summer - lots of people are on holiday, so this month might not be representative.
                - Project description overview is helpful - including a quick summary of what people want help with; recommend that those leading Projects update their project descriptions to indicate what they'd like help with.
                - Do we have the right participation in SDW IG? Encourage IG folks to think about this.
                - Are we trying to do too many projects at once? Does this matter, because we have different folks working on what they're interested in? Noting that the Statistics activity seems under supported and the Describing moving objects activity is effectively dead (it's never started, and the activity lead is not responding to emails).
                - Linda and Jeremy welcome suggestions from the IG about how things could be improved.

> Focus activity: IG folks - please share suggestions about how to improve IG working practices with Linda and Jeremy

OGC Technology Trends

Conference call is planned for Aug 14 Tue, 11:00 AM EDT []. (see also
Looking at the OGC Tech-Trends github repository, no material changes to review at this point.

George's email from July says:
                • all are invited to comment on the Spatial Data on the Web group of Trends; for each Trend there is a GitHub Issue link where you can make comments.

George - will there be anything provided before the conference call next week?

> Focus activity to prepare / review materials. George - what do you anticipate???

Geospatial Web Roadmap
First version of the Roadmap is ready for publication; awaiting Francois to build the pages (he's on holiday).

Outstanding task to list "OGC standards that are "not yet Web-friendly enough" that we could provide
to the OGC Architecture Board (AOB) for their consideration; including a
rationale for each"

> Focus activity: reviewing OGC standards for inclusion on Roadmap … Linda will lead, but keen to get other people's feedback.

Most of the MapML work going on in the OGC Testbed 14 activity: … if you're interested, take a look here.

Some discussion about organising a break out session at TPAC.

Also, discussion in W3C DXWG triggered to look at CRS negotiation as a special case of profile negotiation. See

> Focus activity: what does Peter want to achieve at TPAC? Who does he want to engage with. Linda and Jeremy to assist in developing this plan.

Linked Building Data
No progress, but …

Prompt for Josh to send links (and to do the necessary introductions) relating the work originating from Cesium aiming to create an OGC community standard for geometry serialisation (3D tiles).

SSN Extensions
We've seen no progress on this through July. Here's a reminder of the priority activities:

                1. validation of the SPARQL queries in ED section 4.3 Rules [] - particularly regarding the nested ObservationCollection
                2. understanding the relationship between [ObservationCollection?] and RDF Data Cubes [] - can this be expressed axiomatically?
                3. adding examples to ED section 5. Examples []

SSN Primer
No Progress.

Armin- what do we want to do here, and when will effort start?

SSN/SOSA ontology amendments
No change here. Reminder of the two outstanding issues:

                1. Issue #1006 []: Move hasProperty from SSN to SOSA namespace - on-going discussion
                2. Issue #1022 []: Inverse property for ssn:hasSubSystem - awaiting response from the issue creator as to whether the workaround is acceptable

Plus there's a new bug reported (4-days ago) but no response yet; Linda has added this to the project: Issue #1062 []: SOSA and SSN skos:definition and rdfs:comment do not match in 3 cases.

Two streams of activity; the former should be coordinated by SDW IG …

                1. Profiling CityJSON against CityGML v2 (the current standard)
                2. Developing a JSON encoding of CityGML v3 (this should be pursued within the CityGML SWG)

No progress seen on the profiling; and Hugo is currently on holiday. Would be good to see some progress here. There has been dialogue between Hugo and CityGML SWG on the second item. Expecting more face to face discussion on that topic in Stuttgart.

Linda and Jeremy note that the CityJSON work isn't listed as a Project in SDW-IG. It would be useful to have everything in one place to make it easier to see what's going on. Jeremy will create a new project with links to the work.

One of the key challenges around JSON encoding of CityGML v3 is the apparent disjoint between the theoretical model and the physical encoding(s). Good practice suggests that validation of the theoretical model through implementation and physical encoding can have a positive impact; making the model better. As the SDW IG, do we have an opinion on whether implementation evidence is 100% essential in the standards process - even for conceptual models? Linda will raise a new issue in the SDW IG github repo where we can have our debate about this. It would be good if we can get a conclusion ahead of the OGC TC in Stuttgart (mid-September).

Looking at the Project, Rob is continuing to develop the WebVMT format and syntax. Feedback, as ever, is appreciated. He has also created a public-facing Website for community engagement:

Linda and Rob discussed representation at the OGC Disasters CDS. Given the short timescales, WebVMT wasn't pursued here.

It looks like there is still an outstanding request for help in identifying OGC Members who might be interested in sponsoring Testbed activities. Currently, this is paused until the SDW IG can have a more open debate with the OGC TC (at the Stuttgart meeting) about how we're operating - in particular, that SDW IG is only incubating ideas to the point where working groups can be chartered and NOT trying to circumvent the standards process itself.

Statistical data on the Web
Bill published some updates on the stats-bp/ - adding information about statistics usage / requirements etc. for each of the general Data on the Web Best Practices. This builds on the original work from Andrea Perego.

It seems like Bill isn't getting a lot of support for this activity. The Charter for the OGC Statistics DWG is now published; but there doesn't seem to be anything on the Agenda for the OGC TC meeting in Stuttgart yet.

Is there is any progress getting folks from (UK) Office for National Statistics involved?
At Fort Collins, we talked about trying to make progress with the UN GGIM statistics activity: Expert Group on the Integration of Statistical and Geospatial Information ( - any progress here?

> Bill - is there anything Linda and Jeremy can do to try and build support/contribution for this activity? Is there anything that might get done at TPAC for example.

Describing moving objects
Still nothing here. Request the SDW IG to consider closing this Project.

Spatial data on the Web Best Practices
Jo and Clemens are working on implementation reports: PSMA / G-NAF, and Cadastral / topographic data in North-Rhine Westphalia.

Clemens noted that his goal would be to update our BP implementation report so that the style is consistent with the one from PSMA / G-NAF after Jo's recent edits.

Linda working on a third implementation report about the Dutch Geoportal (Kadaster)

Currently this work doesn't appear to be pushed to the GH-Pages branch. It would be worth cleaning up old branches that aren't required anymore :-)

> Focus activity: further developing the implementation reports.

Time ontology amendments
No progress here. We still have two open issues to resolve. Please refer to the project for details.

New projects
360 Day Calendar []
Dicing or partitioning Ontology for RDF Data Cubes []
Coverage JSON [] - created following discussion in Fort Collins.

Reviewing these new projects, Linda and Jeremy suggest a little more structure and process in managing proposals for new projects.
                1. Use a Project called "Proposals" as a place-holder for new project proposals
                2. Create an ISSUE which describes the proposed Project - this is where the SDW IG can discuss the outcomes/deliverables etc. and who wants to be involved
                3. Assign the ISSUE to the Proposals Project so that we can track progress
                4. Once the SDW IG agree, promote the proposed project to a new Project in its own right - and potentially add it to the W3C Strategy Funnel

Jeremy will create the Proposals Project and the ISSUES for 360 Day Calendar and the Dicing for RDF Data Cubes proposal.

> Focus activity: discussing whether there is interest in pursuing these two projects etc.

2/ The scheduled call w George P to review OGC Tech Trends
See above.

3/ Progress around CityGML / CityJSON
See above.

4/ OGC TC Stuttgart – and the request to talk at the plenary
Scott Simmons is keen for SDW IG to present at the closing plenary, describing what we're doing and how we're working. There are some concerns among OGC members that SDW IG is trying to circumvent the standards process. This isn't the case; we're just providing a home to incubate ideas ahead of full standardisation.

Linda will be in Stuttgart and able to present. Scott, Jeremy and Linda will create some slides to suit.

Currently, Jeremy not planning to be in Stuttgart for OGC TC. Can dial in if necessary.

What else is going on at the TC that SDW IG might engage with or influence?
                - Statistics DWG doesn't appear to be on the agenda
                - Geosemantics DWG - nothing on the agenda yet
                - SensorThings API summit - SSN Extenstions Project looking to include SensorThings examples; action with Josh?
                - UN GGIM update - check possible linkage w Expert Group on integration of statistical and geospatial data
                - CityGML SWG - but this won't cover the CityGML v2 profiling concern which is the interest from SDW IG

5/ TPAC planning
SDW IG meets Monday and Tuesday (22-23 October)
                - Gather interest about the Statistical data on the Web activity
                - Engage with the Linked Building Data CG; 3D tiles and geometry serialisation
                - MapML breakout session on Wednesday - need to be clear about the message and goals / outcomes for this session; Peter is particularly interested in getting visibility with browser vendors
                - Accessibility for Web mapping applications

For IG members: are you planning on coming to TPAC?
For activity leaders: does TPAC provide a good opportunity to progress with your Project - either face to face or remotely?

> Focus activity: to think about attendance at TPAC and (for activity leads) what could be achieved during the F2F meeting.

Once Linda and Jeremy know who is coming/available, they can plan the session.

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Received on Tuesday, 7 August 2018 16:04:37 UTC