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Geospatial Workshop. Geospatial Best Practices for Architects Lessons learned – Metadata. Outline. Background on aeronautical data domain Need for defining metadata Process employed Design overview Lessons learned Things that worked Things that didn’t work References.
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Geospatial Workshop Geospatial Best Practices for Architects Lessons learned – Metadata
Outline • Background on aeronautical data domain • Need for defining metadata • Process employed • Design overview • Lessons learned • Things that worked • Things that didn’t work • References
Aeronautical InformationFAA responsible for releasing National Airspace System (NAS) data to our international partners, distributors and automation systems EnRoute Airspace Route Terminal Fix Procedures Service Airport/Runway Airport/Runway • Aerodromes • Airspace • NAVAIDS & Fixes • Routes • Procedures • Organizations & Services
Airports Concept Aerodrome and Heliport AICM:AD_HP AIXM:<Ahp> Defines the airport or heliport and provides general information. Obstacle at Airport AICM:AD_HP_OBSTACLE AIXM:<Aho> Obstacle at an airport Usage Limitation AICM: AD_HP_USAGE AIXM:<Ahu> Rules describing flights and aircraft that can operate at the airport or heliport. Apron AICM:APRON AIXM:<Apn> Locations where aircraft park and passengers enter and exit the aircraft. Runway AICM:RWY AIXM:<Rwy> A runway at an airport. Taxiway AICM:TWY AIXM:<Twy> Fixed path used by aircraft to travel to and from a runway. Airport Timesheet AICM:TIMESHEET AIXM:<Aht> Operating hours of the airport Runway Direction AICM:RWY_DIRECTION AIXM:<Rdn> Defines runway direction, approach lighting and thresholds. Continuous
Services Concept Service AICM:SERVICE AIXM:<Ser> A service provided by a unit. Organization AICM:ORG_AUTH AIXM:<Org> Organization authority FAA Frequency AICM:FREQUENCY AIXM:<Fqy> Frequency(ies) on which the service is provided Address AICM:ORG_AUTH_ADDRESS UNIT_ADDRESS AIXM:<Oaa>, <Uas> Address of an organization or unit. Center ATC Unit AICM:UNIT AIXM:<Uni> Unit within an organization Flight Services Association AICM:ORG_AUTH_ASSOC UNIT_ASSOC AIXM:<Oas>, <Uac> A parent-child relationship between units or organizations. Timesheet AICM:Timetable AIXM:<Ftt>, <Stt> Operating hours for a frequency or service Working Hours Weekdays 8 to 5 PM
Data is integrated with other data and loaded into aircraft autopilots and air traffic control systems Attention: Taxiway P closed!
Data is also used to produce charts and aeronautical publications
Data is distributed to the general public via graphical maps on FAA websites
The importance of data about data • Underlying mission to keep the skies and flying public safe!!! • Critical for data to be timely and accurate • Essential for data specialists to know: • Who is responsible for the data • What is the source of the data • When is the data effective • Where is the data source • How was the data captured • METADATA is the who, what, when, where and how
Process Employed • Our approach to defining a metadata profile included: • Research • What data is being exchanged? What is the standard for exchanging data about data? • Interview • How have other organizations used metadata? What do the data users want to know about the data? • Document • What is the best way to convey and describe the metadata profile? • Developed UML (universal modelling language) class diagrams of proposed models of the metadata profile
Linkage to ISO19115 : 2003 Geographic Information-Metadata • The structure of the aeronautical metadata profile is based on ISO19115 • The International Standardization Organization has defined a comprehensive metadata standard, ISO 19115: 2003 Geographic Information-Metadata. • Not intended to be a substitution for ISO 19115 • ISO 19115 was developed by Technical Committee ISO/TC 211, Geographic information/Geomatics to define general-purpose metadata in the field of geographic information. • Nor does it completely conform to ISO19115 • ISO19115 is applicable to the cataloguing of datasets, clearinghouse activities, and the full description of datasets, rather than for recurrent messages such as FAA data messages.
Design Overview • Aeronautical data contains information on one or more features including the properties of and relationships between those features EnRoute Airspace Route Terminal Fix Procedures Service Airport/Runway Airport/Runway • In most instances, the metadata for each of these features will differ
The AIXM Metadata Profile • The profile includes six models: • Metadata for the AIXM message • Metadata for an AIXM feature • Metadata for an AIXM feature timeslice • A timeslice allows for temporality – able to exchange data on features described at different points in time • Constraint information • Citation and Responsible Party information • Data Quality information AIXM – aeronautical information exchange model – international data exchange standard
Lessons Learned • Define a metadata model for each feature within the data exchange message and a metadata model for the entire message. • Distinguish our data exchange activities from those discussed in the literature. • Our methodology differs from that discussed in the several papers on metadata standards and mapping efforts that were part of our literature review. • Most of those papers described data domains that were more homogeneous in nature and generally had only one data source.
Lessons Learned • Conduct monthly reviews of the metadata profile with aeronautical information data users and release timely updates • What do they want to know about the data? How will they use the data and the metadata? • E.g., we are going to update the metadata profile to include an element indicating the certification level of the information source, i.e., if the supplier is ISO compliant
References • Metadata Profile white paper available at www.aixm.aero • Validating the model using tools such as MetaModel Integration Bridge • Contact Kim Barnette, The CNA Corporation, supporting the Aeronautical Information Management Group • kim.w-ctr.barnette@faa.gov • 202-267-9235
Background Slides • UML (universal modeling language) class diagrams for each model in the metadata profile • The model will be updated to include a few more suggestions from aeronautical information subject matter experts
Future Updates to Metadata Profile • Move dataIntegrity from Feature to FeatureTimeSlice • It is a numerical value indicating the integrity of the generated TimeSlice. A past timeSlice may have one integrity and a future timeSlice may be at another integrity. • Under Citation – add Process Compliancy - DO200A • Use to indicate the certification level of the information source, i.e., if the supplier is certified under DO200A criteria, or CHAIN or ISO compliant • Update FeatureTimeSlice – include positional resolution • Need to be able to store the horizontal resolution (latitude/longitude) and vertical resolution.