action range

    this.markerLocation = new AR.GeoLocation(poiData.latitude, poiData.longitude, poiData.altitude);

    var actionRange = new AR.ActionRange(this.markerLocation, this.DANGER_RADIUS, {
      onEnter : () => {
        AR.logger.debug('entered danger zone')
        this.alarm.play(-1);
      },
      onExit : () => {
        if (this.alarm.state === AR.CONST.STATE.PLAYING) {
          this.alarm.stop();
        }
      }
    });