How to do a Lucene.Net search for local results based on geographic location?

I'm looking for some info so that users can find local results in their Lucene.Net searches.

I would index the latitude/longitude of the location in the document, and query Lucene based on the users positio开发者_如何学JAVAn and 20 (or 30, 40...) mile range.

The utmost on local search in Lucene is Grant Ingersoll's Location-aware search with Apache Lucene and Solr. Trouble is that Lucene.net lags after Java Lucene, so that these Lucene features available with the rather new Lucene 2.9.0 will take a while to trickle into Lucene.net (Lucene.net 2.4.0 came about a year after Java Lucene's 2.4.0). In the meantime, try Spatial.net in Lucene.net's contrib, or you can try to port Sujit Pal's suggestions from Java to C#.