The BIASDISTSPHERICAL field specifier allows you to boost the score of any document according to its distance from a specified point using spherical coordinates (latitude/longitude).


lat The specified latitude. Specify latitude positions south of the equator as negative.
long The specified longitude. Specify longitude positions west of the Greenwich Meridian as negative.
range The distance in kilometers from the specified latitude and longitude.
maxboost The maximum percentage to boost the result.
LATFIELD The document field containing the latitude.
LONGFIELD The document field containing the longitude.

You must specify two fields in the order latitude:longitude. The fields must be NumericType.



In this example, all documents within 100 kilometers of the point (lat,long)=(52.2,0.1) are given a relevance boost. The maximum boost of 7 percent is given to documents at the given point. The boost decreases linearly down to 0 boost at 100 kilometers.