I'm trying to determine which craft are leaving the persistent "contrails" in my area. They fly higher than commercial craft, and usually on very steep flight paths. I can see them in the air, but they don't show up on ADS-B Exchange, Flightaware, or Radarbox. Am I using the wrong software, or are they untrackable?
Thanks for the explanation.
The flight paths almost resemble those in the NASA diagrams of vapor tracers (https://www.nasa.gov/mission_pages/sounding-rockets/tracers/index.html), but not quite as steep. The craft look like they might be drones. They aren't fighters or commercial planes. They can only be seen with really good binoculars.