Geofence concepts

A virtual boundary for a geographical area on a map.

A group of geofences that is capable of emitting Entry and Exit events, when requested, to evaluate a device's position against its component geofences.

A geometric shape or set of shapes that define the areas to be included or excluded from a geofence. A geofence geometry can be represented as a Circle, Polygon, or MultiPolygon.

A Circle is a point with a distance around it. Use a circle when you want to be notified if a device is within a certain distance of a location.

A Polygon is a list of linear rings which represent the shape of a geofence. This list must include an exterior ring representing the outer perimeter of the geofence, and can optionally include multiple interior rings representing polygonal spaces within the perimeter, which are excluded from the geofence area.

A MultiPolygon is a list Polygon elements which represent the shape of a geofence. The Polygon components of a MultiPolygon geometry can define separate geographical areas that are considered part of the same geofence, perimeters of larger exterior areas with smaller interior spaces that are excluded from the geofence, or some combination of these use cases to form complex geofence boundaries.

For more information about defining geofence geometries, including syntax requirements, limitations, and examples, see GeofenceGeometry in the Amazon Location Service API Reference.