This makes me a bit suspicious of the data. Radar is susceptible to a lot of "clutter". It can see water droplets, waves, clouds, dust, and a lot more. Ever since radar was invented, efforts to separate the target from the chaff have been necessary. Just take a look at a single weather radar sweep (not the composite maps you see on TV, or on weather.com). All will show ground clutter as you look around the radar tower. Until more information is known and experience is gained with this "major sensor upgrade" , I wouldn't rule out radar data processing errors.
If you've ever spent some time in a private airplane on a cloudless day, you can sometimes see a shiny spot on the ground right in the center of where the shadow of your airplane should be. Depending on the terrain and the direction of travel this shiny spot can seem to be moving much faster than the airplane is moving. This is just one example of seeing something that really isn't there.
A few days later, Lieutenant Accoin said a training missile on his jet locked on the object and his infrared camera picked it up as well. “I knew I had it, I knew it was not a false hit,” he said. But still, “I could not pick it up visually.”At this point the pilots said they speculated that the objects were part of some classified and extremely advanced drone program.
But then pilots began seeing the objects. In late 2014, Lieutenant Graves said he was back at base in Virginia Beach when he encountered a squadron mate just back from a mission “with a look of shock on his face.”
He said he was stunned to hear the pilot’s words. “I almost hit one of those things,” the pilot told Lieutenant Graves.