1

How are GeoTIFFs saved in GeoMesa and Accumulo given that it is a key-value datastore? Moreover, which indices are added (if!) and on which fields?

Likewise, for other formats such as:

  • GeoJSON
  • GML
  • KML
Mike Argyriou
  • 1,250
  • 2
  • 18
  • 30
  • A GeoMesa/GeoTiff tutorial but without answering the question can be found on http://www.geomesa.org/documentation/tutorials/geomesa-raster.html – Mike Argyriou Oct 25 '17 at 18:38

1 Answers1

1

GeoMesa's raster support is targeted a narrow set of use cases. The documentation for the raster support (http://www.geomesa.org/documentation/user/accumulo/raster.html) has some of the details for ingest and setting up GeoServer. Raster data does need to be in longitude/latitude (and maybe pre-tiled).

GeoMesa's raster data is indexed by spatial extent solely.

(It may be worth looking at more general raster toolkits like GeoTrellis for Hadoop/Spark-based raster support.)

For vector data, GeoMesa has support via its converter library (http://www.geomesa.org/documentation/user/convert/index.html) for ingesting XML, Json, and other file formats. More generally, GeoMesa implements the GeoTools DataStore API. For any format with a GeoTools DataStore implementation, one could read from that source and write to GeoMesa using straightforward Java/Scala code.

GeoMesa's GeoJson support is documented here (http://www.geomesa.org/documentation/user/geojson.html). For GML, I think the converter library might be a sane approach. For KML, it appears there is an unsupported datastore here (https://github.com/geotools/geotools/blob/master/modules/unsupported/kml/src/main/java/org/geotools/data/kml/KMLDataStore.java).

GeoJim
  • 1,320
  • 7
  • 12
  • Thank you for the info. As far as I understand raster data (even GeoTIFF) are indexed only by their spatial dimension (and not time). Still open question how are the raster data stored in Accumulo data store. – Mike Argyriou Oct 25 '17 at 19:53
  • Also, Geotrellis (correct me if I am wrong) is for distributed processing raster data (WPS?) - does it integrate with GeoServer by acting as datastore (instead of GeoMesa)? It seems that raster data have limited support in GeoMesa (non-overlapping tiles). – Mike Argyriou Oct 25 '17 at 20:24
  • The raster data chunked up, and stored in a serialized format. The keys are geohash representations of the geographic extent of a given chunk. – GeoJim Oct 25 '17 at 20:34
  • GeoTrellis does not currently have a GeoServer integration. GeoTrellis has capabilities which do include local and distributed processing using Spark. – GeoJim Oct 25 '17 at 20:39
  • Regarding the serialization let me add the following reference: https://geomesa.atlassian.net/browse/GEOMESA-504 http://docs.geotools.org/latest/javadocs/org/geotools/coverage/grid/GridCoverage2D.html – Mike Argyriou Nov 05 '17 at 11:28
  • If I wanted to accompany my raster data with a time dimension what would you propose? Sending a 2nd file with the time info? And then how could I retrieve with a single query the raster data that satisfy a tempo-spatial query? Thanks! – Mike Argyriou Nov 11 '17 at 20:24
  • Registering a new ticket since this is a new unrelated question - https://stackoverflow.com/questions/47242572/how-to-retrieve-raster-data-in-geomesa-with-a-single-query-given-tempospatial-se – Mike Argyriou Nov 11 '17 at 20:40
  • Great. I'll respond more fully over there. – GeoJim Nov 13 '17 at 17:54
  • On which table does GeoMesa (Accumulo) store raster data? I didn't manage to find any reference. – Mike Argyriou Nov 16 '17 at 17:33