Spatial Filter in LUcene

Date	2008/11/04
Contact(s)	fxprunayre, jesse
Last edited	Error: Failed to load processor Timestamp No macro or processor named 'Timestamp' found
Status	draft
Assigned to release	to be determined
Resources	Resource available

Overview

Actually GeoNetwork only handle bbox search using Lucene

In a metadata record you could define an extent using

• a description
• a bbox in latlong
• or a gml object

In the search interface, we could search using a geographic keyword (matched to description in the metadata) or bbox matched to bbox in metadata

Requirements:

• handle geographic search between user search criteria (which could be description (eg. canton, commune), bbox, geomtries and metadata records extent information

Proposal Type

• Type: Index
• App: GeoNetwork
• Module: Lucene Index : LuceneSearcher? (main, xml, rss, pdf search) and CatalogueSearcher? (CSW search)

Links

• Documents:
• Email discussions:
• Other wiki discussions:

Voting History

• Vote proposed by X on Y, result was +/-n (m non-voting members).

---

Motivations

Improve spatial search support in GeoNetwork.

Proposal

On indexing procedure, populate a spatial index based on Shapefile (stored in WEB-INF/lucene/spatial). Store the shapefile index in memory to run the spatial filter after the search.

The following operations are supported :

• ENCLOSES
• CROSSES,
• OUTSIDEOF,
• EQUAL,
• INTERSECTION,
• OVERLAPS,
• TOUCHES,
• WITHIN,

Query Examples :

•  http://localhost:8080/geonetwork/srv/en/xml.search?geometry=POLYGON((10%2010,10%2020,20%2020,20%2015,10%2010))&relation=intersection
•  http://localhost:8080/geonetwork/srv/en/xml.search?geometry=POLYGON((10%2010,10%2020,20%2020,20%2015,10%2010))&relation=equal
•  http://localhost:8080/geonetwork/srv/en/xml.search?geometry=POLYGON((7%2046,7%2047,8%2047,7%2046,7%2046))&relation=equal
•  http://localhost:8080/geonetwork/srv/en/xml.search?geometry=POINT(7%2046)

Backwards Compatibility Issues

Risks

Participants

• fxprunayre, jesse