Part of me thinks it is a glitch, the other part thinks it’s cool, but airplanes on the ground at KDEN are being shown. There are a lot of airplanes right at the airport, and most of them have and altitude of 5400 feet and a speed of 25 knots less. Look at the track log for FFT770, I think it is losing mode C so it is jumping back up to 16,000 feet every once in a while, but for the last 20+ minutes listed, the speed is 26 knots or less. The lat/lon are about the same, so I think it is probably parked at the gate.