You can buy an FM UHF receiver and make a yagi antenna.
https://makezine.com/projects/make-24/homemade-yagi-antenna/Very directional, you must point it at the transmitter, so you can verify at least the direction. You can also see it optically.
https://spotthestation.nasa.gov/You can see something travelling across the sky, point your yagi at it, and verify it is emitting radio waves. When you point the yagi away, no signal, they are coming from the same place.
Are we all agreed that something is reflacting or generating light, and a UHF signal is coming from the same place? Are we agreed we know the direction, but not the distance? Are we agreed that there is something traveling across the sky that emits light and rf?
If a second person, say 500 miles away, also determines direction from their position, does this form a triangle? Knowing one side and two angles, we can now determine distance pretty simply.
If you do this with multiple people around the world, one can determine the actual path of the transmitter and light source. This has been done in an uncoordinated way, the web is full of reports of visual sightings and people aiming directional antennas at it.
So, FE world, are we agreed that something is up there at 250 miles, that it emits light and rf, that it is visible/receivable to only the people who would be on that side of RE, that it follows the published path (must be quite a scribble to plot the path on FE)?
FE explanation?