Data Model

Dataset

“The smallest aggregation of data independently described, inventoried, and managed.”​

—Definition of “Granule” from NASA EarthData Unified Metadata Model​

Examples of ODC Datasets:​

  • a Landsat Scene​

  • an Albers Equal Area tile portion of a Landsat Scene​

Product

Products are collections of datasets that share the same set of measurements and some subset of metadata.

digraph product { graph [rankdir=TB]; node [shape=record,style=filled,fillcolor=gray95]; edge [dir=back, arrowhead=normal]; Product -> Measurements [arrowhead=diamond,style=dashed,label="conceptual "]; GridSpec -> CRS; Dataset -> Measurements; Product -> Dataset [arrowhead=diamond]; Product -> GridSpec [label="optional\nshould exist for managed products", style=dashed]; Dataset -> CRS; Dataset[label = "{Dataset|+ dataset_type\l+ local_path\l+ bounds\l+ crs\l+ measurements\l+ time\l...|...}"]; Product [label="{Product/DatasetType|+ name\l+ managed\l+ grid_spec (optional)\l+ dimensions\l...|...}"]; }

Metadata Types

Metadata Types define custom index search fields across products. The default eo metadata type defines fields such as ‘platform’, ‘instrument’ and the spatial bounds.

How the Index Works

../_images/index_sequence.svg

Fig. 6 Sequence of steps when creating an index