Research for: https://github.com/DILCISBoard/CITS-Geospatial/issues/58

• For raster data, Cloud Optimized GeoTIFF (COG) is a promising candidate. However, it is not yet certified as archival format.
• For vector data, the best streaming format candidate (e.g. GeoParquet, flatgeobuf, GeoFeather, vector tiles) is still undecided. However, using streaming formats could also be helpful to make it easier to access archived data.
• For point clouds, there are Cloud-Optimized Point Clouds (COPC).

See also: https://guide.cloudnativegeo.org

Potentially to be added to the Guideline for CITS Geospatial, Appendix 2 -- Long-Term preservation format Profile for Geospatial Raster data using TIFF.

COG is not yet a certified archival format. For example, GDI-DE are listing COG as "under review".

Legacy Compatibility: Traditional GIS software is able to treat Cloud Optimized GeoTIFFs just like normal GeoTIFFs, so data providers only need to produce one format.

Creation: COGs can be created using GDAL (but no yet using QGIS, see https://github.com/qgis/QGIS/issues/41949). For example, here is IrfanView showing a COG created using GDAL:

GDI-DE does not yet list a cloud optimized format for vector data (last checked 2025-09-08).

Potential candidates to be added to Guideline for CITS Geospatial, Appendix 1 -- Long-Term preservation format Profile for Geospatial Vector data using GML include:

Apache Parquet is a powerful column-oriented data format, built from the ground up to as a modern alternative to CSV files. GeoParquet is an incubating Open Geospatial Consortium (OGC) standard that adds interoperable geospatial types (Point, Line, Polygon) to Parquet.

Vector tiles are a way to deliver geographic data in small chunks to a browser or other client application. Clients must then render the data into a visual representation on the fly, typically with the help of a separate stylesheet that describes how the data should look when it is presented to the user.

There is no official standard yet. "Vector tiles" usually refers to Mapbox Vector Tiles or MVT as defined in the Mapbox Vector Tile Specification. Mapbox also offers a guide with visuals explaining how the format works.

MBTiles and PMTiles are two file formats designed for storing large sets of tiles in a single file. Many tools that create vector tiles support outputting to MBTiles or PMTiles archives.

MVTs are great for rendering but they are relatively expensive to create and it is a lossy format.

A performant binary encoding for geographic data based on flatbuffers that can hold a collection of Simple Features including circular interpolations as defined by SQL-MM Part 3.

FlatGeobuf is lossless and very fast to write especially if a spatial index is not needed.

Based on the ideas of Cloud Optimized GeoTIFF and extended for the usage of raster and in particular vector map tilesets. COMTiles are a streamable and read optimized file archive for hosting map tiles at global scale on a cloud object storage.

Deprecated according to https://github.com/brendan-ward/geofeather (last checked 2025-09-08).

Cloud-Optimized Point Cloud (COPC) files are valid LAZ files. (LAZ files are compressed LASER (LAS) files for storing 3-dimensional point cloud data.)

Legacy Compatibility: COPC files are similar to COGs for GeoTIFFs: Both are valid versions of the original file format but with additional requirements to support cloud-optimized data access. In the case of COGs, there are additional requirements for tiling and overviews. For COPC, data must be organized into a clustered octree with a variable-length record (VLR) describing the octree structure.