Back in the day, GPS tracking devices, even Old Saint Nick's whereabouts can be digitally pinpointed on satellite maps.
NORAD (North American Aerospace Defense), the self-professed "Most sophisticated Santa tracking system in the world," explains their process on the NORAD website. It uses "four high-tech systems to track Santa -- radar, satellites, Santa Cams, and fighter jets. Satellites positioned in geo-synchronous orbit at 22,300 miles from the Earth's surface are equipped with infrared sensors, which enable them to detect heat. Amazingly, Rudolph's bright red nose gives off an infrared signature, which allows our satellites to detect Rudolph and Santa."
The real truth is kids can watch videos as Santa flies over various world landmarks. This year, NORAD has also partnered with Google so kids can track Santa via Google Earth.