I've seen a few articles pop up in sources stating that 5G signals will run too close to the 23.8 MHz signal that weather satellites need in order to accurately produce weather forecasts.
One of the crucial bands, says William Blackwell, an atmospheric scientist and engineer at MIT, is around 23.8 GHz. Water vapor absorbs in this microwave band, leaving behind a faint signal that can be read by satellite-mounted instruments that look at the microwave part of the spectrum. The problem now is that telecommunications companies are interested in using parts of the spectrum right next to that water vapor signal.
Jordan Gerth, a research meteorologist at the University of Wisconsin, Madison, has been studying this issue as part of a group at the American Meteorological Society. He says that while the FCC can switch which regions of the spectrum it allocates to phone companies, forecasters are stuck. That’s because water vapor emits a faint signal in the atmosphere at a frequency (23.8 GHz) that is extremely close to the one sold for next-generation 5G wireless communications (24 GHz). Satellites like NOAA's GOES-R and the European MetOp monitor this frequency to collect data that is fed into prediction models for upcoming storms and weather systems.
I've also seen a few dissenting articles claiming that the predictions of a negative impact on weather satellites rely on bad, outdated data, or that they don't take into account how 5G will differ from 4G.
It certainly sounds bad, but NOAA’s doomsday predictions are devoid of scientific justification. When federal agencies raised interference concerns in 2017, the evidence they presented was ultimately withdrawn after its methodological shortcomings were exposed. NOAA’s current claims are based on a similarly flawed study, which has not been released publicly, that doesn’t take into account how 5G networks work in the real world. For instance, it fails to consider that 5G — unlike 4G — will use beamforming to precisely transmit signals to a particular user and prevent out-of-band emissions. In addition, the 5G spectrum will be more than 250 MHz away from the passive weather sensors NOAA is concerned about, providing further protection from interference.
It goes on to argue the relevant weather sensor isn't even in use.
The headline says "No, 5G Won't Ruin Your Weather Forecasts", but the body basically concedes that the 24 GHz bandwidth will need be used with limited power to protect the weatehr forecasts.
I'm inclined to agree with the dissenters, but I also recognize that I am not an expert in signals. To my mind, 200 - 250 MHz seems like a pretty wide gap in between two signals, easy enough for any satellite worth its salt to focus on and filter down to, especially if it's a "focused" signal like 5G is supposed to be.
Will 5G broadcasts in the 24 GHz impact weather forecasts?