How to Feed GPS Data from GPS Sensor to Your Android Phone?

I would like to use GPS data from a GPS sensor that is being placed outside my Android phone. I would like to have the option to switch between my phone's actual location and the "fake" location of the GPS sensor that's placed elsewhere.

Or if it is possible, to "fake" my location without using an additional physical sensor. I have done something similar by enabling the option Allow Mock locations in my phone and using the app Fake GPS. I can then set my location where ever I want to. The problem is that another app runs a check on this option and sees that it is enabled and then stops working.

Does anyone have ideas about how to tackle this problem and where to start?