Am working on a \"US based nearest city search within a given radius\" functionality using Lucene API. Am indexing city\'s lat and long values in Lucene as follows:
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Here's the bleeding edge about Searching Numerical Fields in Lucene by Uwe Schindler, the expert on the subject. You may need to use the older (and slower) ConstantScoreRangeQuery because Lucene.net is a bit behind Lucene, and the class NumericRangeQuery described in the link was not yet released in Java Lucene.