Re: internal vs external
> Is this internal or external signal reception
You won't know. All these organisations are reporting are the outputs of their apps
Radio (broadcast radio) reception surveys used to be based on an aerial 10m above ground level, which was probably sensible when reception required an aerial on the roof, but somewhat overestimated the signal quality for a portable set in the kitchen.
While it would be nice to be able to differentiate between indoor and outdoor signals, the method described seems to be a reasonable way of doing a survey - giving real-life data.