ODC Dataset Metadata Updates

ODC Dataset Metadata Updates.md

ODC Dataset Metadata Updates

Problems

• Too many definitions of spatial extents
  • Including
• Insufficient spatial metadata
  • Not enough information to define the pixel grid
  • Requires CRS + Affine transform + Shape (width, height)
  • Shape and Transform can be different per band
• Storing a Valid Region Polygon as an optional extra

Why

• The eo metadata does not have a schema or any other strict definition
• Requires file access to determine the pixel grid
• OR
• Requires out of band information like pixel size

1. Can not perform efficient native resolution data load()
2. Inefficient and complex database queries

Impacts

• Currently indexed data
• All applications generating data
  • Ingest
  • WOfS
  • Stats
  • Fractional Cover
• All dataset prepare scripts
• Datasets embedded in NetCDF files
• ODC Indexing Code
• ODC Querying Code
• ODC Load Code
• ODC Database Structure
• Likely implies a change of model - No longer store and index inside a verbatim dataset document

Dependencies

It would be very useful to have in place first:

• Database versioning
• Database migrations

References

1. Kirill - ODC Metadata Change Proposal/Discussion
2. Issue 536: Propose to add new field to eo metadata
3. Issue 537: Inaccurate computation of Lon/Lat bounds in geobox_info