WXXM 2.0 Delivering Digital Services Presented By: Aaron Braeckel, NCAR Date: August 28, 2014

Overview The XXM Confusion WXXM 2 Changes Strong and Weak Typing © 2014, University Corporation for Atmospheric Research. All rights reserved.

WXXM / IWXXM IWXXM Managed by ICAO and WMO (international meteorological authorities) Represents internationally-agreed meteorological products from ICAO Annex 3 / WMO No. 49 (currently METAR, SPECI, TAF, SIGMET) WXXM Managed by FAA, Eurocontrol, and other partners Represents aviation-related meteorological products beyond ICAO and WMO requirements Intended to be used in “next-generation” aviation systems in concert with other aviation models – AIXM, FIXM, etc. As of WXXM 2.0, utilizes modeling approaches and concepts from IWXXM Both models meet different requirements but are technically similar: UML and XML components Based on GML 3.2.1 Make use of the Observations and Measurements model © 2014, University Corporation for Atmospheric Research. All rights reserved.

Authority WXXM representations have predated IWXXM representations, such as METAR/SPECI ICAO and WMO have the international responsibility and authority – products in IWXXM are the authoritative form © 2014, University Corporation for Atmospheric Research. All rights reserved.

WXXM History WXXM 1.0 - 2007 WXXM 1.1.0 - 2010 WXXM 1.1.1 – 2010 Initial model release in UML/XML GML 3.2 METAR, SPECI, TAF, SIGMET WXXM 1.1.0 - 2010 Observations and Measurements v1 Additional products Coverage model (predated GMLCOV) WXXM 1.1.1 – 2010 XML Schema fixes © 2014, University Corporation for Atmospheric Research. All rights reserved.

WXXM 2.0 Changes WXXM 2 extends IWXXM – shared design approach Observations and Measurements v2 No longer an explicit Forecast type – now represented as OM:Observation metadata (ICAO/WMO) Replaced WXXM 1.1 Units and Measures in favor of GML-standard units and measures (UCUM) Schemas and other content will be hosted at http://www.wxxm.aero Changed namespace to "http://www.wxxm.aero/wxxm/2.0" © 2014, University Corporation for Atmospheric Research. All rights reserved.

WXXM 2.0 Changes Removed ICAO Annex 3/WMO No. 49-2 products authoritatively represented in IWXXM 1.0 (METAR, SPECI, TAF, SIGMET) Improved weakly-typed representations (coverages), allowing references to external definitions (i.e., registries) Removed regional content, such as PIREP representations Additional ICAO Annex 3 products Additional basic constructs Fixed a number of schema issues © 2014, University Corporation for Atmospheric Research. All rights reserved.

Additional Annex 3 products AIRMET SigWx Volcanic Ash Aircraft Report? © 2014, University Corporation for Atmospheric Research. All rights reserved.

Coverages Intent: provide general-purpose constructs for providing spatio-temporally observed or forecast conditions Categorical and measured quantity values Reference external definitions (i.e., registry) Complex combinations of spatial and temporal conditions Extends GML Coverages to implement ISO 19123 Coverage © 2014, University Corporation for Atmospheric Research. All rights reserved.

Weather Domain Conditions present in many space and time combinations: Multiple points describing a boundary at the same time (front) A collection of observed points at different times (point collection) A series of related points describing a path (trajectory) Multiple times and conditions at the same point (point time series) … © 2014, University Corporation for Atmospheric Research. All rights reserved.

ISO and GML GML ISO Up to one time or geometry Multiple Domain Elements, each with any number of times and geometries ISO © 2014, University Corporation for Atmospheric Research. All rights reserved.

Additional Constructs ForecastTime gml:timePosition that may include any number of forecast lead times RegularTimeList A time primitive that specifies a start time, end time, and regular period RegularForecastTimeList A time primitive that represents a list of forecast times that occur on a regular basis between a start time and an end time. Optional forecast lead times may be specified that apply to all forecast times Amount gml:MeasureType that provides XLink and nilReason support for registry referencing © 2014, University Corporation for Atmospheric Research. All rights reserved.

Typing: Quantities Strongly typed quantity Quantity name in the model Easily validated Explicit Documented Centralized Management Quantity name from producers Extensible Changes not coupled to model release cycles Distributed Management © 2014, University Corporation for Atmospheric Research. All rights reserved.

Usage What do you want to explicitly manage? What needs to be centrally managed? Where the value of checking validity exceeds the cost of maintenance Where the requirements for content or structure are fixed © 2014, University Corporation for Atmospheric Research. All rights reserved.

Strong and Weak Typing Strong and weak types are a design tradeoff No single approach works for all products © 2014, University Corporation for Atmospheric Research. All rights reserved.

WXXM 2.0 Finalize current work Respond to IWXXM 1.1 changes (September) Respond to review feedback Released December 2014 © 2014, University Corporation for Atmospheric Research. All rights reserved.

Contact Information Aaron Braeckel, NCAR braeckel@ucar.edu More Information: http://www.wxxm.aero https://wiki.ucar.edu/display/NNEWD/WXXM © 2014, University Corporation for Atmospheric Research. All rights reserved.