I have an Omega 2+ on an expansion dock running the latest Omega firmware. I want to be able to read the WiFi signal to noise ratio to determine if I have a bad WiFi environment. Reading the signal strength alone doesn't necessarily tell me the whole story.

So far, I have tried a few approaches but none seem to work. The first was using the command

iwinfo

which is supposed to show the signal and noise. Unfortunately the output says that the signal and noise are 'unknown' as shown in the code below. Some information is redacted with XXX's because I don't necessarily want to share it, but anything that is redacted is functioning properly.

apcli0    ESSID: "Network"
          Access Point: XX:XX:XX:XX:XX:XX
          Mode: Client  Channel: 6 (unknown)
          Tx-Power: unknown  Link Quality: unknown/100
          Signal: unknown  Noise: unknown
          Bit Rate: 150.0 MBit/s
          Encryption: unknown
          Type: wext  HW Mode(s): unknown
          Hardware: unknown [Generic WEXT]
          TX power offset: unknown
          Frequency offset: unknown
          Supports VAPs: no  PHY name: apcli0

ra0       ESSID: "Omega-XXXX"
          Access Point: XX:XX:XX:XX:XX:XX
          Mode: Client  Channel: 6 (unknown)
          Tx-Power: unknown  Link Quality: unknown/100
          Signal: unknown  Noise: unknown
          Bit Rate: 150.0 MBit/s
          Encryption: unknown
          Type: wext  HW Mode(s): unknown
          Hardware: unknown [Generic WEXT]
          TX power offset: unknown
          Frequency offset: unknown
          Supports VAPs: no  PHY name: ra0

Pretty strange that just about everything is unknown. Perhaps I am doing something wrong in using it in this way. Next, I tried another command set that I found,

ubus call onion wifi-scan "{'device':'ra0'}"

This command shows the signal strength and RSSI, but no mention of the noise. The output looks like this:

                {
                        "channel": "6",
                        "ssid": "Network",
                        "bssid": "XX:XX:XX:XX:XX:XX",
                        "cipher": "XXXXXXXX",
                        "encryptionString": "XXXXXXXXXXXXX",
                        "encryption": "psk2",
                        "signalStrength": "100",
                        "wirelessMode": "11b\/g\/n",
                        "ext-ch": "NONE",
                        "rssi": "-47"
                }

Is there another way to see the WiFi noise with an Omega 2+ that I just haven't stumbled across yet, or is the Omega 2+ unable to do this due to a hardware limitation? I feel like I have spent days in the docs, to no avail.

<<
want to be able to read the WiFi signal to noise ratio to determine if I have a bad WiFi environment.
<<

It would be better off with something like kismet https://www.kismetwireless.net running in a workstation.

May be, you are looking for a representation like this:
https://en.wikipedia.org/wiki/Kismet_(software)#/media/File:Kismet-2.7.1-screenshot.gif

Kismet has listed the supported wifi hardware in the above site.

The typical capture is in the order of megabytes every second or even more, depending on the environment.

Omega2+ has 802.11 b/g/n, (5 GHz support is optional in "n") up to 150Mbps as per specs, where as n itself is 54-600Mbps.

Also, there are hardware analyzers that meets the needs of a CWAP.

Thanks..