Photographs taken with infrared reflectography and X ray suggested that this rogue painter, while filling in Da Vinci’s sketched study, had made suspicious departures from the underdrawing… as if to subvert Da Vinci’s true intention.
There are no more uses of "infrared" in the book.
Show samples from other sources
The base is patrolled by drones, protected by a twenty-foot-high electric fence, watchtowers, infrared cameras, motion detectors …. and a hundred people just like me, and you know what I can do.
Rick Yancey -- The 5th Wave
The cables also carry video and infrared signals so that the operator can see where the ROV is going.