If your RWR can detect the radar-band it will ping for it regardless of if the source is friendly or not. There is however a setting in options to turn off friendly pings in the RWR:
If something friendly is triggering your RWR even if you have that setting turned off then make a report for it. You can bug report it here: Gaijin.net // Issues (just search a bit first so that you don’t report something that is already reported and known about)