1. Time, Change and Habits inGeospatial-Temporal InformationStandardsGeorge PercivallOGC Chief Engineer11th International Conference on HydroinfromaticsHIC 2014 2014-08-19Copyright 2014 Open Geospatial Consortium

2. Time, Change and Habits in Geospatial-OGCTemporal Information Standards Time and change are fundamental to our scientificunderstanding of the world Standards: means by which we construct realities (Busch) Tacit or formal agreement is needed among users, softwaredevelopers and institutions managing the information Standards from ISO, WMO, ITU, ICSU and OGC General talk with direct applicability to hydrology A robust framework for geospatial-temporal information isnow coming into place Newly established OGC Temporal domain working group.Copyright 2014 Open Geospatial Consortium 3. A little Physics and Philosophy of Time Philosopher Immanuel Kant Time is not an empirical exposition. For neither co-existence nor succession would be perceived by us,if the representation of time did not exist as foundation a priori Physicist Lee Smolin Time and its passage are fundamental and real. Hopes and beliefs about timeless truths and timeless realms aremythology Organization of this talk1. Temporal coordinate systems for arranging events and change2. Events and Change observations connected by causal relationsOGCCopyright 2014 Open Geospatial Consortium 4. Agenda GeoSpatial Temporal Standards Temporal Coordinate Systems Moving Features Fluid Earth Coverages Visualizing maps and events over time Events and Time Series Process models and the Model Web Emergence of forms and habitsOGCCopyright 2014 Open Geospatial Consortium 5. OGCTemporal Coordinate Systems Historically, time for geographic features treated asthematic feature attributes, i.e., independent of space. ISO 19108: Geographic information -- Temporal schema, Feature can be represented as a spatiotemporal object. Path of a moving object as a curve with coordinates in x, y and t ISO 8601: Representation of dates and times Represent dates: YYYY-MM-DD in Gregorian calendar Times in UTC Julian Dates as alternative to Gregorian Calendar ITU TF.686-3 to define Coordinated Universal Time (UTC) time interval of second in SI UnitsCopyright 2014 Open Geospatial Consortium 6. OGC Temporal Coordinate Reference URIs Temporal CRS Temporal Coordinate System (CS) one single axis with Unit of Measure (UoM), label, direction [future|past] Temporal datum Binds relative temporal axis to fixed point in time Origin element, a date+time concatenation ex: 2012-12-21T00:00 OGC policy for temporal coordinate reference systemdefinitions in OGC Standards Specifies construction and http URIs for temporal CRSs Such coordinate reference systems could be compound withgeospatial ones, to build spatiotemporal geometric spaces Vote to adopt policy scheduled to close on 2014-08-28OGCCopyright 2014 Open Geospatial Consortium 7. Moving features in a temporal CRS Prism: leaf andtrajectory (sweep) inspatio-temporalspace Leaf: snapshot of amoving feature at atimeOGCCopyright 2013 Open Geospatial ConsortiumtimeSpatialplane1 prism = 1 leaf + 1 sweep(&attribute)End leaf of tracksid=1Id=211:11:20.835 11:11:26.215 11:11:28.021 11:11:30.127(C)(B)(D)(A)ISO19141 a basis for OGC Moving Features Standard 8. OGCMoving Features Geographic features whose locations change over time. ISO 19141 Geographic information - Schema for moving features Trajectory: curve that represents the path of a point in the geometryof the moving feature Only rigid moving features that do not deform OGC Moving Features Standard Working Group Implementation standard to be based on conceptual 19141. CSV for encoding lightweight data records i.e. for applicationsinvolving large data volumes and real-time response GML for Moving Features to encode more complex spatialinformation.Copyright 2014 Open Geospatial Consortium 9. OGCGeographic Coverages Geographic phenomena fall into two broad categories discrete features and continuous coverages Schema for coverage geometry and functions OGC Abstract Spec for Coverages; adopted as ISO 19123. Web Coverage Service (WCS) OGC web-based interface for access to coverages Multi-dimensional coverage data for access over the Internet. netCDF encoding standard OGC encoding of digital geospatial information representingspace/time-varying phenomena An extension of WCS was developed for netCDFCopyright 2014 Open Geospatial Consortium 10. A coverage is a feature that associates positions within a boundedThat is to say -- a collection of features that share a common regulargeometryOGCCoveragesspace to feature attribute valuesCopyright (c) 2009 Opengeospatial Consortium Examples Raster image Polygon overlay Digital elevation matrixLatitude -->Longitude --> 11. OGCSlide Source: Ben DomenicoGrids and Station Observations 12. Coverages applied to Fluid Earth Systems GALEON: Geo-interface for Air, Land, Earth, OceansNetCDF Interoperability Experiment Interoperability between GIS data and Fluid Earth Systems (FES), Parameters (e.g., pressure, temperature, wind speed) as continuousfunctions in 4-dimensional space and time Behavior of parameters governed by partial differential equations CF-netCDF Core and Extensions Primer Climate and Forecast (CF) conventions provide semantics Naming conventions for files, dimension and variable names Geospatial and temporal coordinates, coordinate systems andprojectionsOGCCopyright 2014 Open Geospatial Consortium 13. NetCDF-CF dataset contentOGC 13Slide Source: Stefano Nativi, Ben Domenico 14. Visualizing maps and events over time WMS with Time-Dependent or Elevation-Dependent Data an OGC Best Practice Use of dimensions time and elevation in WMS standard Use of a newly defined dimension reference_time time axis for some relevant referent time other than validity time E.g. start times of numerical weather calculations or sending timesof warningsOGCCopyright 2014 Open Geospatial Consortium 15. Validity Time of Forecasts: Range Nominal Start Time of Forecast: PointNominal Start Time 00-12 12-00 00-12 12-00 00-12 12-002009-11-26T00:00 * * * *2009-11-26T12:00 * * * *2009-11-27T00:00 * * * *OGC2-D Time axis for Forecast DataValidity Time of Forecasts2009-11-26 2009-11-27 2009-11-28Copyright 2014 Open Geospatial ConsortiumTable from OGC Document 12-111r1 16. Climate Challenge Integration Plugfest Demonstrated standards-basedinteroperability between applicationsfor Climate Change analysis Plugfest launched at FOSS4G But participation was welcomed from allwhether open or proprietaryOGC Network of online data services(WCS, WFS, SOS), online analysisservices (WPS, WCPS, WMS), andgeospatial client applications thatexercise those serviceshttp://www.opengeospatial.org/projects/initiatives/ccip2009Copyright 2014 Open Geospatial Consortium 17. Climate Challenge Integration PlugfestOGCCopyright 2014 Open Geospatial Consortium 18. OGCChange of focus:from Coordinate Systems to Change Coordinate systems while unreal are useful for ordering Spatial coordinate systems are used to identify location of objectsand to define spatial relations Temporal coordinate systems (time) is used to order events andmeasure time between events Calendars and Clocks are anchored with real Events Change is a phenomena of interest. Capture change as events Model change as processesSecond half of talk focuses on Events and ProcessesCopyright 2014 Open Geospatial Consortium 19. OGCEvents Event: action that occurs at an instant or over an interval of time (GML) Snapshot: status of the whole at a moment. TimeSlice: only feature properties that have changed History: sequence of events of an object Event: anything that happens or is contemplated as happening at aninstant or over an interval of time (Sensor Web Enablement) SWE event service: provides notification of events, i.e., changes, to clientssubscribed to an event type. Event Service applicable across OGC web service standards standards Event enable WFS and a standalone Sensor Event Service in OGC Testbed 10 Event definitions treat temporal characteristics as fundamental; spatialcharacteristics are not inherent to events In contrast to homogeneity of 4D space of co-equal spatial referencesystems and temporal reference systemsCopyright 2014 Open Geospatial Consortium 20. OGCEvents and Observations Observation: an act associated with a discrete time instantor period through which a number, term or other symbol isassigned to a phenomenon (O&M 2013) Act of Observation assigns a value to a property of a feature. If the property is non-constant, the value is a function or coverage. WaterML2.0 Implementation of Observations for hydrological observations The core aspect of the model is in the correct, precise description oftime series. For exchange of time series with appropriate metadata to allowcorrect machine interpretation and further analysisCopyright 2014 Open Geospatial Consortium 21. class Figure 2: Observ ation CoreFeatureT ypeOM_Process1 +procedureProcessUsedFeatureT ypeOM_Observ ation+ parameter: NamedValue [0..*]+ phenomenonTime: TM_Object+ resultTime: TM_Instant+ validTime: TM_Period [0..1]+ resultQuality: DQ_Element [0..*]constraints+metadata 0..1{observedProperty shall be a phenomenonassociated with the type of the feature of interest}{procedure shall be suitable for observedProperty}{result type shall be suitable for observedProperty}{a parameter.name shall not be used more thanonce}instanceOfFeatureT yp...GFI_FeatureT ypeGFI_PropertyTypeDomain1Range+theGF_FeatureType 1OGCMD_MetadatatypeAny{root}metaclassGF_FeatureType{root}metaclassGF_PropertyType{root}DataT ypeNamedValue+ name: GenericName+ value: AnyObserv ationContext+ role: GenericNamePhenomenon+observedProperty1+propertyValueProvider0..*+featureOfInterest0..*+relatedObservation0..*+generatedObservation0..*MetadatainstanceOf+result+carrierOfCharacteristics0..*WaterML2 Part 1: Time series data 22. OGC/WMO Hydrology Domain Working Group4-Year International Effort WaterMLHydrology Domain Working Group formedOGC at WMO Commission for HydrologyNovember 2009A time series for one variable at one locationTechnical Meetings Each 3 MonthsFour Interoperability Experiments(Surface water, groundwater, forecasting)Annual week-long workshopsInvolvement by many countriesAcknowledgements: OGC, WMO, GRDC, NWS,CUAHSI, BoM/CSIRO, USGS, GSC, Kisters, .2008 2009 2010 2011 2012 23. International Standardization of WaterML Hydrology Domain Working Group standards for water data: WaterML 2.0 suite organizing Interoperability Experiments (IEs)focused on different sub-domains of water Chairs: Ilya Zaslavsky (USA) Tony Boston (Australia) Silvano Pecora (Italy)OGCIterative Developmenthttp://external.opengis.org/twiki_public/bin/view/HydrologyDWG/WebHome 24. HydroDWG: Suite of Water Information StandardsOGCWaterML2Part5:River Channel(RiverML, underdevelopment)WaterML2Part1:Water QuantityObservation(OGC10-126r4)WaterML2Part2:GaugingObservation(OGC13-021rX)WaterML2Part3:Water QualityObservation(OGC14-003rX)CSML3:Atmospheric-watercomponentSoilML:Soil-watercomponentWaterML2Part4:Groundwater(GWML2, underdevelopment)TimeSeriesML(underdevelopment) Suite of Water Information Standards:towards the identification, observationand representation of hydrologicfeatures using standardsHY_Features,common hydrologicfeature model(OGC11-039r3) 25. OGCProcess Models Events captured from the past and predicted for the future. We perceive passage of time; an arrow from the past to the future. Spacetime incorporates ever more events, concretizing as timeevolves: time progresses, events take place and history is shaped(Ellis 2013) Predict future events using models Models estimate some phenomena while ignoring most of the world All models are wrong, some are useful (Box 1987) Lets look at some standards for interfaces to modelsCopyright 2014 Open Geospatial Consortium 26. What is the OpenMI? An interface standard (API) for: run time (in memory) data exchange betweenmodels, databases & other components Whose purpose is to: improve ability to model complex scenariosApplicationUser interfaceInput dataHydraulicsOutput dataApplicationUser interfaceInput dataRainfall/RunoffOutput dataOpenMI28 27. Linking modelled quantitiesRainfall Runoff Model River ModelAccepts ProvidesRainfall(mm)Runoff(m3/s)Temperature(Deg C)Evaporation(mm)Accepts ProvidesUpstream Inflow(m3/s)Outflow(m3/s)Lateral inflow(m3/s)Abstractions(m3/s)Discharges(m3/s) 28. What?When? Where?10:00 12:301.0 1.01.01.51.01.01.21.11.21.0e1e2e3e4e5t1 t2The data model30 29. Current status of OpenMI OpenMI 2.0 available and in use since 2010http://sourceforge.net/projects/openmi/files/Version_2.0.0.0/ OpenMI 2.0 submitted to OGC for acceptance Approval Date: 2013-12-06 Publication Date: 2014-05-26 http://www.opengeospatial.org/standards/openmi Document 11-014r331 30. OGCWPS access to Models OGC Web Processing Service (WPS) Protocol for web-based control of algorithms, handling variety ofinput and output formats Multiple applications of WPS for access to predictive models WPS access to hydrologic models USGS Geo Data Portal processing services available using WPS enviroGRIDS integrated WPS with GreenLand for web access tohydrologic modeling and land cover/land use analysis WPS protocol within HydroModeler environment, built on OpenMI(Castronova 2013) Towards a Geoprocessing Web using WPS an entire Volume ofComputers & GeosciencesCopyright 2014 Open Geospatial Consortium 31. OGCCopyright 2014 Open Geospatial ConsortiumSlide source: Fei Liu, NOAA ESII @GEOSS Future Products Workshop, March 2013 32. Model Interoperability - An Evolution(Source: S. Nativi, CNR, GEOSS Future Products Workshop)OpenMIESMF 33. Model Web and Sensor Web in GEOSSSocietalBenefitsDecision SupportAssessmentsSensor Web Remotely-sensed In situPolicyDecisionsOn-going feedback to optimize value and reduce gapsModel Web Oceans Ice Land Atmosphere Solid Earth BiosphereInteroperabilityand standards 34. OGCModels without Equations All models are wrong, and increasingly you can succeedwithout them (P. Norvig, Google) Parameterized models being replaced by large databases ofunstructured information Steps of Model Building (Gupta and Nearing 2014)1. Process Model: conceptual representation, physical principles2. Parameterized Model: system parameterization, e.g., PDEs3. Computational Model: numerical interpolation and integration Generate input-state-output simulations without explicitly usingstrong parameterizations (equations)? Model interoperability based on Process Model only? Focusing on the emergent formsCopyright 2014 Open Geospatial Consortium 35. OGCEmergence of forms Current state of Spatial-temporal modeling Moving features limited to non-deforming shapes with semanticmeaning defined in advance Grid-based coverages over time are without semantically identifiedshapes How do semantically significant forms emerge over time? Complexity is improbable. It requires explanation. Sequence whichimplies a strong ordering of events in time. (L. Smolin) Are there general principles that guide the emergence of formsacross all geospatial-temporal processes? Charles Peirce: All things have a tendency to take habits. For every conceivable real object, there is a greater probability ofacting as on a former like occasion than otherwise. This tendency itself constitutes a regularityCopyright 2014 Open Geospatial Consortium 36. Agenda GeoSpatial Temporal Standards Temporal Coordinate Systems Moving Features Fluid Earth Coverages Visualizing maps and events over time Events and Time Series Process models and the Model Web Emergence of forms and habitsOGCCopyright 2014 Open Geospatial Consortium 37. Time, Change and Habits in Geospatial-OGCTemporal Information Standards Coordinated framework for geospatial-temporal standardsnow coming into place OGC Temporal Working Group Time as a first-class alignment concept with that of space Coordinate with other OGC WGs and stakeholder groups Open to non-members and OGC members http://www.opengeospatial.org/projects/groups/temporaldwg Heraclitus The river where you set your foot just now is gone those watersgave way to this, now this. (Fragment B41)Copyright 2014 Open Geospatial Consortium