Speaker
Description
Heliophysics dataset discovery has historically been partitioned by subdiscipline and by archive, forcing researchers and client developers to query solar and space-physics holdings through separate interfaces with incompatible query semantics. The HelioData API (https://api.heliophysics.net/api) addresses this with a single REST/JSON interface over the SPASE-described holdings unified by HDRL.
The service exposes a browsable root of eight collections: datasets (7793 registered datasets) plus seven controlled vocabularies — observatories (3112), instruments (4494), quantities (1302), repositories (199), regions (24), measurementtypes (21), and spectralranges (12). Rather than relying on free-text search, each vocabulary endpoint returns stable identifiers (earth-magnetotail, MagneticField, numberflux-differential:alphaparticle) that compose directly into faceted dataset queries. The controlled vocabulary thus becomes the query grammar: a client enumerates the legal facet space before querying, eliminating the guesswork and brittle string matching typical of federated science search. The quantities vocabulary uses a compound quantity:species identifier scheme, and the region facets derive from HDRL's contribution of a ~200-concept heliophysics taxonomy to the Unified Astronomy Thesaurus, giving the facets an externally governed semantic basis. The 199 registered repositories span NASA, ESA, JAXA, NOAA, NSF, and university archives, making the index genuinely cross-agency.
I will describe the service architecture, the SPASE-to-API mapping, and its use in an ongoing CCMC collaboration to resolve observational datasets relevant to a given model run. Plans to further map between the API concepts and other vocabularies will be discussed.