Variables @ NASA GESDISC Mahabal Hegde ADNET Systems/NASA GESDISC maha.hegde@gmail.com

How are they exposed? Subsetting Services Examples: Mirador, Simple Subset Wizard Visualization Services Examples: GIOVANNI, OGC Services

Variables in GIOVANNI Attributes

Variables in GIOVANNI Facets (Attributes)

Variables in GIOVANNI Keywords

Variables in GIOVANNI Names, Units, Resolutions, Color Palettes, Data range

Variable Attributes: Examples Keywords Examples: Land-only, Unfrozen Disciplines Examples: Hydrology, Aerosols Resolutions (Spatial + Temporal) Examples: Monthly, 1°

Variable Attributes: Examples Source Examples: AIRS, GPM Measurements Examples: Air Temperature, Soil Moisture

Variable Attributes: Examples Color Palettes Example: <sld url=”net_radiation_sld.xml" label="Blue-Yellow-Red (Div), 65” />

Variable Attributes: Examples Discovery Methods Example: osdd=“https://api.echo.nasa.gov/opensearch/granules/descriptor_document.xml?clientId=eed-edsc-ops&shortName=AQUARIUS_L3_SSS_RAINCORRECTED_CAP_MONTHLY_V4&versionId=1&dataCenter=PODAAC”

Variable Catalog Curation Editor OPeNDAP Apache Solr CMR GCMD or DIF Document Data Archive GIOVANNI

Sources of Variable Information Attributes Collection Metadata Spatial coverage Platform/Instrument Discovery method Granule metadata Temporal Coverage Documentation + Subject Matter Expertise Spatial and temporal resolution Units Color palettes Valid data range Dimensions Measurements Disciplines Sample granule & OPeNDAP URL

Variable Metadata: Challenges Some attributes known only to domain experts. Example: Data range, Color palette, Measurement

Variable Metadata: Challenges Metadata provider may not be aware of how it is consumed. Example: Long name

Variable Metadata: Challenges Questionable quality when they exist. Example: Typos, Not so relevant keywords

Variable Metadata: Challenges Incomplete metadata Example: Temporal information, Wavelength values

Variable Metadata: Challenges Several standards or conventions to choose from. Conventions are recommendations and are not mandatory.

Variable Metadata: Challenges Tedious to curate: just do it.

Looking forward … Variable based services in a single user interface Data Lists (Predefined, User-defined)