Does any body knows how to run a passive scan for networks in range from an app, even if the Wi-Fi is OFF? I know this is possible for sure, the app "Wifi Anal

Does any body knows how to run a passive scan for networks in range from an app, even if the Wi-Fi is OFF? I know this is possible for sure, the app "Wifi Analyzer" does it. As you can see on: https://snag.gy/cfYTmy.jpg https://snag.gy/cfYTmy.jpg The only network related permission this app requests is "Wi-Fi connection information" so I'm wondering how they do it, and if it is possible to do so from a background service. I will like to run scans periodically and show up a notification once a predefined network is in-range.