Not quite Linux but this is a good Android app if you have such a device handy:<br>
<br>
<a href="https://play.google.com/store/apps/details?id=com.farproc.wifi.analyzer">https://play.google.com/store/apps/details?id=com.farproc.wifi.analyzer</a><br>
<br>
Cheers<br>
Neil