public function bd_encrypt($gcjLat, $gcjLon) {
		$x = $gcjLon; $y = $gcjLat;  
		$z = sqrt($x * $x + $y * $y) + 0.00002 * sin($y * $this->x_pi);  
		$theta = atan2($y, $x) + 0.000003 * cos($x * $this->x_pi);  
		$bdLon = $z * cos($theta) + 0.0065;  
		$bdLat = $z * sin($theta) + 0.006; 
		return array('lat' => $bdLat,'lon' => $bdLon);
	}