TT AvData Discussion 2025 Jun 25 - wmo-im/iwxxm GitHub Wiki

Details

2025-Jun-25, 12:00-13:30 UTC, Microsoft Teams

Agenda

  1. IWXXM 2025-2:

    • Review on the updates in the second commit on IWXXM schemas
      • Comments in PR:
      • Package SIGMET:
        • Corrected all latitudes and longitudes (the figures in the original TAC are in degrees and minutes) in sigmet-multi-location-VA.xml (Issue #339)
      • Package SWA:
        • Updated example spacewx-A7-3.xml (by Jan)
      • Package VAA:
        • Changed element iwxxm:sourceElevation to iwxxm:sourceElevationAMSL to indicate its vertical reference (Issue #29)
        • Made corresponding changes to va-advisory-A7-2.xml
        • (Not implemented. Decision required) iwxxm:volcano which uses metce:EruptingVolcano is having an element which is not nillable (but is required to be nil under certain situations) (see Issue #344). Two possible solutions: Update METCE or create elements in VAA schema to replace metce:EruptingVolcano. What would be our preference?
      • Package WAFSSigWxFC (Needs to change version from 1.1.1RC2 to 1.2.0RC2):
        • Allowing iwxxm:WAFSSignificantWeatherForecast to have extension
      • Package VONA:
        • Replaced enumeration of Colour Code in VONA with codelist iwxxm/AviationColourCode derived from 49-2/AviationColourCode the latter of which has been deprecated with the removal of the Colour Code item in VAA
        • Made corresponding changes to vona-A7-1.xml
        • Allowing iwxxm:VolcanoObservatoryNoticeForAviation to have extension
      • Package QVA:
        • Allowing iwxxm:QuantitativeVolcanicAshConcentrationInformation to have extension
      • Package MeteorologicalFeature:
        • Changed the reference of codelist MeteorologicalPhenomenon from 49-2/MeteorologicalFeature to iwxxm/MeteorologicalFeature.
        • Made corresponding changes in WAFS-Example.xml, qvaci-Example.xml and vona-A7-1.xml
        • Allowing iwxxm:MeteorologicalFeature to have extensions
      • Packages measure and common:
        • (Not implemented. Decision required) Mark in Issue #340 suggested to include measure.xsd in common.xsd. A more complete way is to move all 5 features in measure.xsd to common.xsd. By doing so and deleting the empty measure.xsd we can have a simpler schema structure too. Shall we proceed?
      • General:
        • Split schematron rule IWXXM.nilReasonCheck into two: IWXXM.nilReasonCheckLegacy checks nilReason in Legacy reports (METAR, SPECI, SIGMET, AIRMET, VAA, TCA and SWA) and IWXXM.nilReasonCheck checks the rest. Made corresponding changes in WAFS-Example.xml, qvaci-Example.xml and vona-A7-1.xml
        • Fixed schematron rule TAF.TAF-2 which fires wrongly (Issue #323). Added version number 1.0.0RC2 to iwxxm.sch
        • Copied documentation/manual from Branch MoC-FM205 (PR #349)
    • Review on the updates in the second and subsequent commits on code lists
      • Comments in PR:
        • Removed columns "publisher", "manager" and "owner" and rename column "modified" to "publishDate" in container CSV. Modified makeIWXXMEntities.py to suppress inclusion of content in "publishDate" in TTL and RDF files (by Anna)
        • Changed http://www.wmo.int/pages/prog/www/WMOCodes/WMO306_vI1/VolumeI.1.html to https://library.wmo.int/idurl/4/35713 in 306_container.csv (by Anna)
        • Changed WMO No.49-2 to Annex 3 + PANS-MET and made relevant adjustments in 49-2_container.csv (by Choy)
        • Emptied cells in column "related" if it is the same as those in column "URI" in entity CSV (by Anna)
        • Changed 30\u00B0N to 30 degrees N (by Anna)
        • Removed 49-2/VolcanicAshConcentrations and iwxxm/VolcanicAshConcentrations code lists as they are no longer required (by Anna)
        • Removed 49-2/observation-type and 49-2/observation-property code lists (by Anna and by Anna)
        • Changed column id to URI and reorder the columns (by Anna)
      • Created iwxxm/nil and iwxxm/MeteorologicalFeatures code lists to prepare for transition from common and 49-2, as well as iwxxm/AviationColourCode (derived from previous 49-2/AviationColourCode which has been deprecated due to its removal from VAA) to replace an enumeration in VONA
      • Updated makeIWXXMEntities.py to suppress the generation of TTL files for common/nil and bufr/codeflag as they are not supposed to be under TT-AvData's purview, but their RDF files are still generated for use with iwxxm.sch
      • Created workflow build.yml to run makeIWXXMEntities.py after a PUSH to GitHub

  2. Decisions to be made

    1. IWXXM

      • Include measure.xsd in common.xsd?
      • Make metce:EruptingVolcano/metce:eruptionDate nillable or replace it by new elements in VAA?

    2. Code lists transition plan

      • Create new/fork existing code lists and put under http://codes.wmo.int/iwxxm for new packages
      • For common/nil, a fork has been created in iwxxm/nil. Since the schemas will not mandate the use of which nil we will need to add in the examples and TAC-to-XML-Guidance.txt which packages should use which nil
      • Since new packages should normally be an extension of MeteorologicalFeature, we will need change its references to code list from 49-2 to iwxxm
        • This will affect existing packages including WAFSSigWxFC and upcoming packages VONA and QVA and we will need to inform them of the intended changes
      • Transition of WAFSSigWxFC could be more complicated since it is using bufr4/codeflag code lists. Transition of them may be more complicated, as we normally do not keep the existing code list naming, like http://codes.wmo.int/bufr4/codeflag/0-20-008. Existing code lists http://codes.wmo.int/49-2/SigConvectiveCloudType and http://codes.wmo.int/49-2/CloudAmountReportedAtAerodrome are examples of forks of BUFR code flag tables with completely different names

    3. Publication of revised code lists with no associated changes to IWXXM schemas

      • Registry and its entities are marked with applicable IWXXM versions
      • This means if a new IWXXM version is published, applicable registries and their entities will have to be refreshed by adding the new IWXXM version
      • What about in case there is a need of updating one or more code lists without the need of updating the schemas? Do we need to refresh the IWXXM version? In that case code lists will effectively be another column in the IWXXM compatibility table

    4. Are we going to submit information on Aviation Headings to be posted on the WMO Community website through FT2025-2 too?

      • An Appendix to ICAO Doc.9766 is being prepared and on it there will be descriptions on the new WMO Headings. It originally points to WMO No.386, but as there is no information on the new headings they will change it to the URL of this part of the WMO Community website. This appendix is supposed to be published by Nov 2025.
      • Shall we put an "under construction" web page before we have approval to post Aviation Headings there?

Notes

  • Choy welcomed the team
  • Choy talked about the recent changes on the schemas and examples
    • the team discussed issue https://github.com/wmo-im/iwxxm/issues/344 (see note in issue)
    • Choy explained that unchanged packages will not be updated to have new iwxxm codelists, the introduction of iwxxm codelists will be applied to the newer packages that are not in production yet
  • the team decided to remove measures.xsd see notes in https://github.com/wmo-im/iwxxm/issues/340
  • the team continued to discuss the plan for moving codes into the iwxxm registry and how to introduce versioning to the iwxxm codelists
    • Choy also added a version to the schematron; should these versions be listed in the compatibility table?
  • the team discussed the new web page for ICAO AHLs and decided to post it in the WIS activity area
  • the team discussed the plan for finalizing the proposal for fast-track- Choy will send out an email to the team next week, inviting the team to review by July 10 with the goal to circulate this proposal by end of July.

Actions

Next Meetings

(TBI)

Invitees / Attendance

Name Country/Affiliation Attendance
Boon-leung CHOY (Chair) Hong Kong, China X
Wilberforce KIKWASI (Member) Tanzania  
Jan KOROSI (Member) HMEI/IBL X
Mark OBERFIELD (Member) USA  (Retired)
Raquel SALAZAR (Member) Costa Rica  
Boonchai TEPYOSE (Member) Thailand  
Dirk ZINKHAN (Member) Germany  
Albert MOLOTO (Member) South Africa  
Shan CAO (Member) China
Sunny CHAN (Guest) Hong Kong, China
Paul HERSHBERG (Guest) USA  X
Anna MILAN (Secretariat) WMO X
Martin Michalek (Guest) HMEI/IBL X
Boris BURGER (Guest) HMEI/IBL