What is ATS???

Personally I have seen them cheming us from as low as maybe 8000 feet, but usually they do it at 20,000-25,000 feet. Normal jet traffic is at 30,000-35,000 feet. Small planes under 12,000 feet.

Easy to triangulate the height of the chems by driving your car on a straight road from directly under them, out to a 45 degree angle. The distance you drove equals their height in the sky.