where do i have to look in order to understand location based search concepts?

Inorder to understand - cartessian tiers,how are they contributing in location based search - What is happening internally when we give query to solr like http://localhost:8983/solr/select/?q=name:Minneapolis AND _val_:"recip(hsin(0.78, -1.6, lat_rad, lon_rad, 3963.205), 1, 1, 0)"^100 and other functions like g开发者_C百科hhsin(),sqedist(),dist() .how is it working to retrieve relevent records?

Can any one suggest me any link that will help me understand all these concepts better.

Thank you.

For the big picture, here's Grant Ingersoll paper on location-aware search in Lucene and Solr.

For the details, try the Solr Wiki FunctionQuery page or Ingersoll's Fun with Solr Functions.