+1 with K6CCC
An AREDN node will display SNR = N/A when no other AREDN nodes are heard on the same Channel, SSID, and BANDWIDTH.
To detect other AREDN users nearby, you may do a Wi-Fi Scan on each of 5, 10, and 20 MHz bandwidth.
That will display detectable nodes even if they have a different SSID.
I think it is rare that a network has nodes with non-default SSIDs.
An AREDN node will display SNR = N/A when no other AREDN nodes are heard on the same Channel, SSID, and BANDWIDTH.
To detect other AREDN users nearby, you may do a Wi-Fi Scan on each of 5, 10, and 20 MHz bandwidth.
That will display detectable nodes even if they have a different SSID.
I think it is rare that a network has nodes with non-default SSIDs.
73, Chuck