Premise: Assume that the infamous Wolf 359 star system has one habitable planet and a second, habitable or not, upon which the Wolvians have developed a mining operation. The two planets (maximum separation: 3 AU) have receivers with a -200 db threshold. The transmissions are focused between the two planets, so they would not be continuously detectable by Earth (if detectable at all) as only the signal aligned with Earth when the two planets appropriately line up could be detected.
For the purpose of this question, assume that the ecliptic of both star systems are perfectly parallel on an arbitrary X-Y axis with one another.
The Z-axis difference between the two systems should be taken into account.
Assume space between the two planets is clear of any debris.
The planets are talking with each other, not with Earth. Our detection is incidental to their activities. Please assume the Wolvians are unaware of us.
Please ignore the fact that the actual Wolf 359 star (a red dwarf) is unlikely to promote life.
Do not assume the use of satellites to get around the line-of-sight problem when the planets are on opposite sides of their sun. The transmissions may originate from planet-based transmitters or from satellites in orbit around the planets, but may not be bounced off of satellites in orbit around the sun.
Assume the transmissions from each planet are continuous such that the signals could be represented by cones, emanating from each planet in the direction of the other.
Assume the technology on Earth that is currently available to SETI.
Question: Would the interplanetary transmissions in the Wolf 359 star system be detectable by Earth today?
Best Answer: The best answer will consider as many of the factors complicating this premise as possible. A defensible signal strength, nature of the focus, window of opportunity for detection, all three dimensions, etc. The best answer will produce, with reasonable extrapolation from current technology, a defensible solution for what signal strength would be used by the Wolvians and its detectability here on Earth.
Worldbuilding Justification: Building alien worlds that can be detected by Earth without Star Trek-ish exploration requires a better understanding of how they would justify the power needed for transmissions we can detect. Thus, from the perspective of building a civilization at Wolf 359, could that civilization have a justifiable reason (e.g., a mining operation on another planet in their own system) for pumping out the energy needed to be detected?
The linked question intrigues me because it assumes Earth would be pumping out on a general basis power levels that could be detected at very long distances. Assuming human logic (the Vogons would disapprove of that generalization), there isn't a reason to do that. There will likely never be a reason to do that. This suggests that we need an off-planet reason to pump out that kind of power — but off-planet solutions are directional, not global. Though simplified, this question suggests that the civilizations SETI's looking for are substantially more technologically advanced than we are and that the detection of their presence would strongly suggest specific applications of that technology.