Is there a police station in Beijing Airport?

I am US citizen traveling to Manila from USA. I am arriving at 4:50am and have a 15 hour layover in Beijing. My flight to Manila departs same day at 8:00pm. I will not be staying in a hotel. I will be doing a layover tour to see The Great Wall. Do I have to register in a local police station? Is there a police station in the aiport that can take care of this? Please advise. Thank you!