The Wireless Survey function lets you run a scan to detect “nearby” (based on signal strength) Wi-Fi networks. The results show SSID name, signal strength, channel, and other network information. This provides crucial details which help you to decide on which channel to run your Tomato device's Wi-Fi network(s).
NOTE: While this tool is fully functional, you may find more direct and presentable data using other tools, such as some of the “Wi-Fi scanner” apps available for smartphones. Those apps also provide the advantage of being able to easily move the “scanner” when needed, much more easily than is possible with a fixed router/AP.