ElasticSearch geo distance filter

simple explanation

//i create doc item using Elastica in PHP, database has about 150 000 items

$mapping->setProperties(
        array(
            'id' => array('type' => 'integer'),
            'name' => array('type' => 'string'),
            'quality' => array('type' => 'integer'),
            'type_id' => array('type' => 'integer'),
            'country' => array('type' => 'string'),
            'city' => array('type' => 'integer'),
            'location' => array('type' => 'geo_point')          
            )
        );

//i use curl lib in PHP, in common the query is following:

curl -XGET "http://localhost:9200/database/object/_search" -d '
{     "size" : 2000,   
      "filter" : {
            "geo_distance" : {
                "distance" : "4km",
                "location" : [48.85341, 2.3488],
                "optimize_bbox" : "none",
                "distance_type" : "arc"
            }        
}'

//returns 789 items