private boolean measurementIsValid(Measurement measurement, OpenCellIdCell cell, double r) {
		
		double distanceToCellTower = Geom.sphericalDistance(
				cell.getCellTowerCoordinates().getX(), 
				cell.getCellTowerCoordinates().getY(), 
				measurement.getCoordinates().getX(), 
				measurement.getCoordinates().getY());
		
		if(distanceToCellTower > r) {
			return false;
		}
		
		int signalStrength = measurement.getSignalStrength();
		
		if(signalStrength >= 32)
			return false;
		
		else if(signalStrength >= 0 && signalStrength <= 31) {
			int signalStrengthDBM = (2*signalStrength)-113;
			measurement.setSignalStrength(signalStrengthDBM);
		}
		return true;
	}