Results > Manipulate Result Relevance > Use the BIAS Field Specifier to Boost Relevance > BIASDISTSPHERICAL

BIASDISTSPHERICAL
The BIASDISTSPHERICAL field operator works in a similar way to the BIAS field operator. It allows you to bias the score of results at query time according to the proximity of the specified field to a given location, specified using a latitude and longitude value.
Specify BIASDISTSPHERICAL using the format:
FieldText=BIASDISTSPHERICAL{lat,long,range,maxboost}:LATFIELD:LONGFIELD
where,
 
is the distance in kilometers from the specified coordinates. If the fields contain the coordinates of a location that is within this distance of the specified coordinates, the results weight increases or decreases according to the specified percentage.
is a percentage in the range –100 to 100. If the value of the field is within the specified range, the score of the result increases or decreases according to how close the value is to the specified optimum.
You must specify two fields in the order latitude:longitude. The fields must be of NumericType.
For example:
FieldText=BIASDISTSPHERICAL{52.2,0.1,100,7}:LAT:LONG
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 zero boost at 100 kilometers.