This wiki has been archived and is now read-only.

Detailed planning BP document

From Spatial Data on the Web Working Group
Jump to: navigation, search

Work on the Spatial Data on the Web Best Practices is done in shortish cycli we call sprints. Three more sprints are expected until the end of April, resulting in a new version of the BP document every 6 weeks or so. Outline:

December 2016 - beginning of February 2017

Sprint plan:

  • Action 242: Restructure the document to move the summary to the top and remove the template.
  • Action 232, 233, and 234: Further work on BP 4 (indexable spatial data), including addition of examples and a description on what is indexed.
  • Action 247: Rewrite of section 7 Coordinate Reference Systems.
  • Action 248: Further work on BP7 (use HTTP URIs) + BP14 (Links to related resources) based on discussion at the december 2016 face to face meeting in London.
  • Action 240: Remove BP17 (crowdsourcing) from BP document.
  • Outreach to get review from wider public at the end of this sprint (Ed).
    • Including horizontal review by W3C groups on accessibility, security, internationalization etc. (Phil)

Backlog - To do

February - mid March 2017:

Dataset metadata

  • BP2: Remove (but retain stub for now so numbering of BPs does not change) and move content / problem description to Conclusions where we will discuss remaining gaps.
  • BP2 owner: Jeremy Tandy

Spatial data vocabularies and file-formats

  • BP10: priority provide guidance on choice of vocabulary for describing spatial data; inevitably will need to talk about file formats too; aim to include @BillRobert’s thoughts about “balancing performance against operating costs” when making those choices; key aspect is the use of MULTIPLE FORMATS (and/or multiple vocabularies) - see DWBP BP14: Provide data in multiple formats
  • BP10 owner: Bill Roberts

  • do we want/need to introduce a “samePlaceAs” property?
  • Jeremy Tandy to seek consensus via mailing list

  • BP14: describing the links between spatial things is dependent on the vocabulary choices (see BP10); update in light of amendments to BP10 etc.; add references to Appendix B “auth sources of geographic identifiers”; @lars said he check up about the Beacon format; we also need to consider the “hypermedia” implications of links (e.g. what can we do to help data consumers know what to do with the resource at the end of the link); also see below proposal to delete BP15 and migrate any remaining useful content from there into BP14
  • incorporate the following "linking" topics from BP9: vocabularies / properties for describing topological spatial relationships / “spatial predicates” (e.g. equals, disjoint, intersects, touches, within, contains, overlaps and crosses); lack of evident best practice in using common vocabularies / properties for direction and distance relationships (distance relations “at”, “nearby” & “far away”; directional relations “left”, “in front of” & “astern”)
  • BP14 owner: Jeremy Tandy

  • Decide if Appendix A still provides value; if so then update else remove it
  • move to following sprint?

Spatial data access and APIs

  • BP11: use of “convenience APIs” is covered in DWBP §8.10.1; review SDW best practice to determine what is different (seems to be talking about how you might conveniently expose data in an SDI through Web-friendly APIs?) and update content such that it ties back _properly_ to DWBP
  • BP11 owner: Clemens Portele (assisted by Bart van Leeuwen)
  • Remove contents of BP12 and BP13 but retain stubs in order to keep BP numbering intact for now.
  • Remove section 12.8 Dealing with large datasets - this is already sufficiently well covered in the revised BP11.

Coordinate Reference Systems

describing properties that change over time

  • BP6 is pretty much complete except for two examples (approach #2: version history of change to extent of city of Amsterdam, approach #3: GPS track (data stream?) from an alpine marathon runner) … @linda thinks Geonovum might be able to craft these examples
  • BP6 owner: Linda van den Brink


  • note: the editors plan to re-order the best practices during the next sprint; so where we are removing best practices this time around we will leave empty "stubs" so make sure that the numbering remains consistent for the upcoming WD release ... @jtandy thinks that his brain can't cope with number changes just at the moment!

  • update CRS introductory material to refer to engineering CRS (used for built environment) and relating these back to geographic CRS; and that SRS used in things like cellular microscopy is out of scope
  • owner: Ed Parsons

  • BP9: update to reflect use of local and relative coordinate reference systems used to reflect the built environment; reflecting the best practices evident in the large body of information already published about built infrastructure; noting that sensors are often described using these "engineering" CRS; objective is to provide sufficient information for users (?) to relate the engineering coordinate positions to geographic coordinate positions; include insights from AR community and their "egocentric" perspective (ref. discussions with @cperey; ACTION #128); which is increasingly important in order to see spatial things rendered / represented in AR tools & browsers
  • BP9 owner: Josh Lieberman

  • Remove BP2: (provide context required to interpret data values) We had a HUGE discussion on the mailing-list about UoM etc., but don’t think we made any conclusions; currently this best practice is vague and not actionable; propose to remove BP2 in this sprint _unless_ someone can write content to make this (i) specifically relevant to spatial data, (ii) actionable, and (iii) best practice that is evident in the wild
  • Jeremy Tandy to seek consensus via mailing list

  • Remove BP15: (use links to find related data) this is (i) the flip side of BP14, and doesn’t really say anything new, (ii) consumer oriented rather than for data publishers (so out of our amended scope) … migrate any useful content to BP14 and delete
  • owner: Jeremy Tandy

  • Remove §14 Narrative but parse for useful information that may be incorporated elsewhere in the BP doc before we discard it to the annals of GitHub history
  • owner: Linda van den Brink

  • Remove §13 Other best practices - pending merge of BP16 into BP10, and consolidation of CRS material in BP3 and BP17
  • owner: Linda van den Brink

  • Resolve the 3 ReSpec warnings currently showing on the Editor's Draft; this may require the material on privacy concerns (added following discussion during London F2F) to be extracted from the Scope and put into a separate section.
  • owner: Linda van den Brink

Mid March - end of April 2017:

TARGET DATE FOR "VOTE TO RELEASE": Wed 10-May-2017 (proposed)

"how to use" section

  • Jeremy Tandy | Update §11: How to use these best practices based on material in BPs 8, 10, 14 (etc.); continuing to reference best practices from both DWBP and SDW-BP (Done)
    • Having re-read the material in this section, and the additional suggestions given in the wiki page, it seems as though almost everything is now covered elsewhere in the BP doc; the restructuring has helped the document flow and we have obviously added a lot more material into the document for the BPs themselves.

Best practices

How to test and Evidence (e.g. cross-ref with UCR Requirements) sections for each best practice

  • Principle author for each best practice | Make sure these sections are complete and correct
    • Josh Lieberman | BP13 (old BP1) (Done)
    • Jeremy Tandy | BP7 (old BP3) (Done)
    • Clemens Potele | BP2 (old BP4) (Done)
    • Peter Parslow | BP14 (old BP5) (Done)
    • Jeremy Tandy | BP11 (old BP6) (Done)
    • Jeremy Tandy | BP1 (old BP7) (Done)
    • Andrea | BP5 and BP6 (old BP8) (Done)
    • Josh Lieberman | BP9 (Done)
    • Bill Roberts | BP4 (old BP10) (Done)
    • Clemens Portele | BP12 (old BP11) (Done)
    • Jeremy Tandy | BP3 and BP10 (old BP14) (Done)
    • Jeremy Tandy | BP8 (old BP17) (Done)

Benefits section for each best practice

  • Linda vd Brink | Assign the benefits for each best practice (see also, the Benefit Appendix below) (Done)

BP3: Choose the coordinate reference system to suit your user's applications

  • Jeremy Tandy | Minor edits (as discussed during Delft F2F) (Done)

BP4: Make you data indexable by search engines

  • Jeremy Tandy | Minor edits to reflect discussion about 'indexable dataset metadata' (e.g. dataset landing pages) during Delft F2F (Done)
  • Clemens Portele, reviewed by Lars Svensson | Fix concerns about applicability of sitemaps (Done)

Best Practice 5: Describe the positional accuracy of spatial data

  • Peter Parslow | Hasn't been changed in a while; looks good, but review and amend if necessary (Done)

Introductory text for section 12.5 Spatial Data Vocabularies

  • Josh Lieberman | Clarify intro to §12.5 - different ways to describe position not location etc. (Done)

BP8: Provide Geometries in a web friendly way

  • Andrea | Work continues (see 'green note' at end of BP8 for the outstanding work) - note that we agreed that we would not cite the use of non-identifiable / non-addressable geometries (as per data.geohive.ie example) as a best practice (Done)
  • Andrea, with help from Josh Leiberman | refactor into 2 best practices (a/ general geometry publication; b/ multiple geometries) (Done)
  • Andrea | Reference new File formats and vocabularies appendix (Done)
  • Andrea | Elaborate on simplifying geometries including guidance on deciding when doing this is a good idea and when not. See comments on SDW WG Public list. (Done)
  • Andrea | Check that we have satisfied GitHub Issue 251 (Done)
  • Andrea with help from Ed | Refer to GeoJSON Text Sequences as just one of the methods to work with large geometry objects; see GitHub Issue 656 (Done)

BP9: Describe relative positioning

  • Josh Lieberman | Add data-snippets to examples 22, 23 and 24

BP10: Encoding spatial data

  • Bill Roberts | Work continues (ref. out-of-band email with list of changes); “where you fit on the ‘spectrum’ of SDI to simple HTML page (e.g. publishing information about the village fête)”; include Address and other non-geometric mechanisms to describe location (Done)
  • Bill Roberts | Reference new File formats and vocabularies appendix (Done)
  • Bill Roberts | Consider if/how to add reference to EO-QB; see Kerry's email point no. 1 (Done)
    • She quotes “For example, if using a Linked Data approach, one option is to keep all data in a triple store; but hybrid approaches are also possible,“ - EO-QB could be the missing example, e.g. "In EO-QB satellite imagery metadata is stored in a triple store but observational data is stored in HDF5 and served through DGGS and query processing middleware that materializes RDF triples only in response to a SPARQL query for them." ... [EO-QB] added to the local bibliography so that it can be referenced.
  • Bill Roberts | Consider how to incorporate references to coverage data types and choices about their encoding; e.g. [COVERAGE-JSON] and [EO-QB] - see Kerry's email point no. 3 (Closed - updated version of BP makes it clear that we don't need to treat coverage data as a separate thing)

BP11: Expose spatial data through 'convenience APIs'

  • Clemens Portele | Minor edit to reference spatial operators (Done)
  • Clemens Portele | Minor edit to reference 'geometry simplification' in BP8 (once Andrea has provided an update) (Done)

BP14: Publish links between spatial things and related resources

BP17: State how coordinate values are encoded

  • Andrea | Add a note about WKT coordinate order (in some implementations?) (Done)
  • Jeremy Tandy | Amend to state that approach #4 should always be done (with ref to BP1), combining with another approach when possible (Done)


  • Linda vd Brink, Jeremy Tandy | Populate section 14. Conclusions once we have the majority of the content in place; should we talk about the big changes that these BPs drive? or gaps in best practice? or echo DWBP’s §10 Data on the web challenges graphic? Linda suggests we (re-)use some of the text from her paper - which includes some discussion on interoperability gaps. (Done)

Open challenges include:

  1. How to express units of measurement in an interoperable way (see discussion thread and summary which provides a reasonable outline of the problem) (Done)
  2. Content negotiation (as recommended in DWBP Best Practice 19: Use content negotiation for serving data available in multiple formats only works for media type - not for choosing data vocabulary / profile or CRS representation ... (note the draft charter for Dataset Exchange WG (DXWG) who aspire to provide a REC for "content negotiation by profile") (Done)
  3. Link discovery (Done)

File formats and vocabularies

  • Andrea and Bill Roberts | Merge slimmed-down lists from Appendix A (common formats) and intro material for section 12.5 Spatial Data Vocabularies (list of common vocabularies) into a new Appendix; “a couple of lines per entry” … try to map onto the four categories of spatial data publication (spatial analysis & spatial data management; data integration; web applications; simple Web publication) (Done)
  • Josh Lieberman | Add green note about new OGC Spatial Ontology into this appendix (see GitHub Issue 382) (Done)


  • Linda vd Brink | Add new section (or appendix) with benefit descriptions and x-ref to each best practice (table and graphic), as per DWBP; we said "empty boxes in the benefit map are OK" - the spatial data on the web best practices might not coincide with all the benefit categories from DWBP (Done)

Requirements cross-reference

  • Payam Barnaghi | Update Appendix C to include cross-reference from both SDW-BP and DWBP against the requirements in the UCR doc to make sure we’ve covered everything … and if we find gaps, we’ll need to call these out explicitly (Done)

Update: PB: The table is now available at: [1]

  • Payam Barnaghi | Add new Appendix with mapping from SDWBP to DWBP; draft material is on the wiki at BP Mapping (Close - not adding this)

Update: PB: The table is now available at: [2]


  • Chris Little | Update Appendix D. Glossary - review, remove the yellow highlight, check definitions & amend as necessary ... see also GitHub Issues 212 and 39 (Done)


  • Linda vd Brink | Update Abstract to reflect Linked Data approach without reliance on RDF (Done)
  • Linda vd Brink | Re-order / re-structure the BP document; including updating introductory text sections for the re-ordered groups ... Linda to come back with some proposals (Done)
  • Jeremy Tandy | Incorporate the proposals made by Peter Parslow in his email to SDW Public Comment list (Done)
  • Jeremy Tandy | Add a Contributors section (following the list of Editors) to the document header (as per DWBP to reflect the hard-working working group members and also update Appendix E. Acknowledgements (Done)
  • Jeremy Tandy | Add list of namespace prefixes of the vocabularies/schemas used in the BP document (Done)
  • Linda vd Brink | Check that we are consistent in use of "geospatial" and "spatial" terms (see GitHub Issue 206) (Done)
  • Linda vd Brink | Ensure consistent style of text and reference citation - see GitHub Issues 193 and 222 (Done)
  • Jeremy Tandy | Ensure that each best practice when referring to others takes account of the re-ordered sequence of best practices (Done)
  • Linda vd Brink | Check that all the "How to test" statements are action oriented; e.g. "Check that 'a', 'b' and 'c' can be found" (Done)
  • Jeremy Tandy | Update SOTD section (Done)
  • Linda vd Brink | Update "changes since last release" section (Done)
  • Jeremy Tandy | Check for W3C PubRules compliance and broken links (Done)
  • Jeremy Tandy | Check for American-english spelling - and other spelling mistakes (Done)
  • Linda vd Brink | Tidy up commented out sections of document (Done)

Issue resolution

  • Ed Parsons (to lead) | Review and resolve the outstanding Public Comments (Only one issue remains outstanding)
  • Linda vd Brink (to lead) | Review and resolve the set of open issues in GitHub (Only one outstanding ISSUE (#237) - to be discussed during OGC TC @ St Johns)
    • during the Delft F2F we suggested scheduling a 3-hour teleconference block to work through the remaining issues (Done)

Outstanding public comments

May - June 2017:

  • Time buffer period
  • Publish final version of BP document.

Editorial 3