If my understanding of physics is correct (and if it isn't, I'd appreciate a correction because this would be some fundamental problem), if they stuck the antennas in a crater that's opaque to most radio frequencies, and make a wall around the edges - making sure no point in the (extended) inner surface can see anything else other than the inner surface and the sky, then there shouldn't be a problem with radio interference.
Radio waves are light, and to a good approximation, radio emitters are like lightbulbs. On Earth, we have a problem because atmosphere scatters radiation. On the Moon, if you can't see the radio source directly or through a set of reflections, its signal won't get to you, period. So if you stick the antennas at the bottom of a well, they should not get any interference even if there's plenty of human activity nearby.
One problem I see is that human activity near the telescopes could create dust clouds, and those would definitely scatter radiation - and in low gravity, it could take some time for them to settle. I imagine it would make sense to prohibit rocket launches and construction work involving explosives in the vicinity of the telescopes.
The crater shown there is already the kind of well I'm describing - its edges go above the nearby surface, and at least on the diagram, at no point the inner edge can see the rest of the Moon's surface.
Edit: It seems that diffraction around edges and electromagnetic ground waves are two quite different phenomena. (A third separate effect being a refractive index vertical gradient in the atmosphere causing diffraction, acting as a waveguide.) EM ground waves require that the ground is partially conductive, which the Earth is, but I suspect the Moon isn't particularly because it's dry. Still, diffraction will occur.
"However, the angle cannot be too sharp or the signal will not diffract. ... Lower frequencies diffract around large smooth obstacles such as hills more easily."
Fortunately we can control our intentional emissions really well and could test for unintentional ones, most intentional communications will be in the higher bands anyways because it's higher bandwidth, the antennas are more manageable, and it's the standard currently anyways.
Right. I'm mostly worried about dust reaching near-escape velocities, allowing it to take its sweet time as it falls back down. I'd have to do some math to see if this is an actual problem - it might be that it's very hard to create such a cloud.
Those satellites would be operating in higher frequency bands than most radio telescopes care about. If it does turn out to be an issue they can also be programmed to stop transmitting when they’re ‘in view’ of the telescope.
I believe that even despite the low gravity of the moon, dust settles out quite quickly. There's just nothing to stop it from free-fall, nothing to push against or mix with.
Radio waves are light, and to a good approximation, radio emitters are like lightbulbs. On Earth, we have a problem because atmosphere scatters radiation. On the Moon, if you can't see the radio source directly or through a set of reflections, its signal won't get to you, period. So if you stick the antennas at the bottom of a well, they should not get any interference even if there's plenty of human activity nearby.
One problem I see is that human activity near the telescopes could create dust clouds, and those would definitely scatter radiation - and in low gravity, it could take some time for them to settle. I imagine it would make sense to prohibit rocket launches and construction work involving explosives in the vicinity of the telescopes.
EDIT: I'm looking at the picture in the TFA:
https://www.nasa.gov/sites/default/files/thumbnails/image/ni...
The crater shown there is already the kind of well I'm describing - its edges go above the nearby surface, and at least on the diagram, at no point the inner edge can see the rest of the Moon's surface.