http://franz.com/ns/allegrograph/5.0/geo/nd#inCircle

Returns the subject or subject and object of triples within an N-Dimensional radius

The center of the region is specified by the ordinate values given for the several geo ordinates. In spherical ordinate systems exactly one ordinate of type :latitude and exactly one ordinate of type :longitude must be provided. In cartesian ordinate systems one or more ordinates of type :cartesian must be provided. A minimum and maximum ordinate value must be provided for each of the remaining ordinates, as for nd:inBoundingBox.

This can return the subject of the matching triples or the subject and the N-Dimensional literal (which is in the object). For example: 

?event nd:inCircle (ex:locationPredicate :lat 37.805 :lon -122.1217

                                          :radius 0.1 :units :km

                                          :time-min "2015-11-04T08:45:00Z"

                                          :time-max "2015-11-04T09:00:00Z") .

or 

  (?event ?wherewhen) nd:inCircle (ex:locationPredicate ...) .

For spherical coordinates a :units argument is accepted specifying the units of the :radius argument. It may be :km (default), :miles, or :radians of arc.

Notes

The following namespace abbreviations are used:

The SPARQL magic properties reference has additional information on using AllegroGraph magic properties and functions.