RADAR_DETECTED - log issue

[Goose]

Any one knows what that is :
2015-08-30T10:43:35.890795+00:00 AP10 %RADIO-4-RADAR_DETECTED: Radar found on channel 64 freq 5320 MHz

what is the idea behind this message ?
Thanks
Goose

[Michael McNamara]

It's expected when radar signals are detected in that specific RF channel.

DFS is a spectrum-sharing mechanism that allows wireless LANs (WLANs) to coexist with radar systems. It automatically selects a frequency that does not interfere with certain radar systems while operating in the 5 GHz band. DFS is a feature of ETSI BRAN HIPERLAN/2 and IEEE Standard 802.11h.