CathInfo.com

My forte is TV DX, not ham radio (though I do hold a Technician license) or other types of audio reception.  I can tell you that the site rabbitears.info allows you to do a signal search based upon your location, and provides Longley-Rice "heat maps" as well, which take into account terrain, and are of course based upon a GE model.  Those maps tend to hold up when compared with actual reception of various stations at any given location.  The stations it predicts I will get are indeed receivable (I have a copse of pine trees to the north of my property, which makes reception in that direction more difficult, and which the heat maps don't take into account, but in all other directions it's smooth sailing), and the further out you get from the transmitter, terrain and elevation have their way with the signal.  If you can get out over a completely unobstructed area (such as a body of water), the heat maps predict a gradual diminution of signal as you get further away from the TX, then a sharp drop-off after about 100 miles tops.  It would be interesting to have some kind of boat, go out to the limit that the heat maps predict, and see if the signal does, indeed, completely vanish.  Now, as to whether this would prove FE or GE could depend on various factors, such as the downtilt of the signal (ordinary TV signals are not like microwaves, they fan out from the top of the TX and, so I have been told, are flattened out above the TX, as there is no point sending a signal straight up in the air).

Here is a sample map showing a station directly on the Florida coast (WJXT Jacksonville FL, RF channel 18, tower height 997 feet at 670 KW).  The "sharp drop-off" is at the outer edge of the salmon-colored band.  The PSIP information (i.e., the channel number you see on your TV set) is channel 4 (4-1, 4-2, and so on for the various subchannels), but that is not the actual RF channel, when the FCC forced all stations to switch over to digital, using different channel allocations in the vast majority of cases, they allowed the broadcasters to retain the same channel numbers on PSIP, for continuity of marketing.  WJXT has been channel 4 in Jacksonville forever, so even now that it is broadcast on RF channel 18, the viewer still sees channel 4 on the screen.  It's complicated.

I would add to the list that one should be open to the possibility of a dome, allowing for signals to possibly reflect off of that depending on the scenario, and of course, more than just open to the possibility, since Sacred Scripture quite clearly describes a physical dome, so we as Catholics must believe it.

Even Dr. Sungenis departed from his original "firmament is space" hypothesis, realizing that it was inadequate, and moved first toward the Planck fabric explanation, which I think again he found inadequate (speaking to some intellectual honesty there on his part), since the Planck fabric could not have the properties attributed to the firmament (preventing water from inundating the earth during the Flood), and moved toward the Ice Firmament theory as described in his latest video series from Kolbe that appears to have had the plug pulled on it.  He was working on a series on "How God Created the World in Six Days", but it appears to have been cancelled after Day 2.  I do suspect that both Kolbe and he got so much heat about the giant space ice ball theory (from the same types that deride FE, ironically, and with whom he had joined forces against FE) that they pulled the plug.  I wrote to Kolbe asking them what happened, since I had purchased Day 1 and Day 2, with the hope that I could get the entire series.  I may request a refund to see if that will inspire them to tell me why they aborted the series.