SOROCA is a highly scalable Open Source Earth Observation (EO) catalog. It has been developed on European Space Agency (ESA) request to speed up and horizontally scale up, fast growing Earth Observation image catalogs.

These catalogs usually store the metadata of remotely sensed images in PostgreSQL database, extended with PostGIS; this solution (relational SQL database) does not offer enough possibility for horizontal scaling (except e.g. using the STADO extension, which nevertheless was not sufficient for our purpose). This was actual at beginning of the project at least, since a new issued generation of PostgreSQL can be strong rival.

This product offers a new solution based on the MongoDB (no relational) database, as a highly scalable and reliable storage solution, and the Pycsw server as a skeleton for the new catalog server (SOROCA), developed in conformance with the OpenSearch standard 10-032r3.

The Mongo database did not include a full satisfactory spatial functionality, and due to this reason it has been extended. Data in the SOROCA catalog are divided into blocks of the same size and distributed to several nodes. During the query execution, all nodes including relevant data will be used in parallel.

Catalog interfaces manage the access to metadata storage, i.e. they search for records based on a client query, and return results in RDF, ATOM, KML, generic XML or WKT format. Query results describe the real data (images) and their source, providing the link to the actual repository for download.

For more information read the SOROCA_Poster