I don't think you'd even need anything fancy. Here's the list of things that are true of most of the surveillance aircraft I've found: Flies in circles Fli

I don't think you'd even need anything fancy. Here's the list of things that are true of most of the surveillance aircraft I've found: Flies in circles Flies over one region for hours Flies at around 5000 feet altitude Squawks 4414 or 4415 Uses a callsign that starts with JENA or JENNA Registered owner in Bristow VA, Greenville DE, Wilmington DE, or Manassas VA I have some simple code that highlights planes that are flying in circles so that I can take a closer look at them.