DGGSs (Discrete Global Grid Systems) provide a new way to organise, store and analyse spatio-temporal data. This document contains a normative definition for DGGS and informative annexes. Annex B discusses the theoretical basis for equal area Earth DGGS, and Annex C discusses DGGS’s historical background. At the heart of DGGS is a new Referencing system. Spatial and temporal RSs described elsewhere by ISO/TC211 and the OGC (Open Geospatial Consortium) fall into two types:
Referencing by coordinates (ISO 19111:2019), and
Referencing by identifiers (geographic in ISO 19112:2019 & ordinal era in ISO 19108:2002).
In spatial Referencing by identifiers, the only required geometry is an extent, which may be expressed as a simple bounding box. Formal geometry need not be defined and sometimes follows societal whim. Similarly in ordinal temporal RSs, the topology of ordinal era’s are known, but the start and finish times are often only an estimation and are not required by the data model. DGGSs introduce a third type — Referencing by identifiers with structured geometry. A single parent global geometry is chosen to define the dimensionality and orientation of the region of space-time occupied by the DGGS — it’s global world.
Request For Comment (RFC)
OGC Seeks Public Comment on Candidate OGC SensorThings API Extension: WebSub Asynchronous Messaging Standard