Sources are going to be questionable because detection range is something any military keeps secret. That said, try this: https://militarywatchmagazine.com/art

Sources are going to be questionable because detection range is something any military keeps secret. That said, try this: https://militarywatchmagazine.com/article/su35-fourth-sensor-irst-hunt-stealth https://militarywatchmagazine.com/article/su35-fourth-sensor... 90km range claimed Also, consider why many surface to air missile systems have optical tracking capabilities. Surely those are effective or they wouldn’t keep adding them to new models, right? Even the F-35 itself uses cameras to search for and track targets at long range.