These optical targets in the Arizona desert were built for calibrating the cameras of a spy satellite network called the Corona program. Similar to the huge bar codes found across the U.S. southwest, also used for testing high-altitude cameras, these targets are glyphs meant to be seen from the sky: fixed points of focus and orientation for classified machines soaring through space far above.
https://atlasobscura.kinja.com/arizona-still-holds-scars-from-the-cold-war-space-race-1560544308
