Now in the third dimension! The axes might not be an exact km representation, but are good enough for this video. The figure shows ADS-B lat/long data in the Maryland / Baltimore Washington International (BWI) airport area. The blue square shows my receiver location, and the points shows ADS-B MSG 3 locations of aircraft relative to the receiver and color coded by their altitude. The stratification at high altitudes (>6km, red/orange) are cross-country flights. The aircraft points at middle altitudes (~5km, green/cyan) show flights in a holding pattern or aircraft that are starting their decent or climb. Aircraft points below low altitudes (<2km, blue) show flights landing and taking off from the BWI airport. Projecting this down onto lat/long the low-altitude flights trace the two main BWI runways.
My goal is to incorporate a map and some indication of flights landing or taking off in the next version.