ionospheric-related vs. ionosphere-related [closed]

I am not sure which of the following sentences is correct (or which is the "best" version):

1. [...] texts describing mainly ionospheric-related experiments.
2. [...] texts describing mainly ionospheric related experiments.
3. [...] texts describing mainly ionospheric experiments.
4. [...] texts describing mainly ionosphere related experiments.

My understanding is that 1 is better than 2 as it is a compound adjective. I am not sure though if the second adjective (related) is really needed in this context as ionospheric basically means something related to the ionosphere (please correct me if I'm wrong). Initially I was favoring 1, but currently I am not sure if not 3 (or 4) is the better choice. Any hints or comments are greatly appreciated!

Solution 1:

If “ionospheric experiments” is scientifically correct, it is the best answer as the shortest, clearest and least ambiguous.

By scientifically correct, I mean “do the experiments involve the ionosphere directly?”. I assume so. Only if they are indirectly or tangentially related to the ionosphere would “ionospheric-related” be the choice.

Let me illustrate why X-related is not the same as X.

As a biological scientist I can do experiments to find out how some biochemical sequence of reactions operates, e.g. is A converted to B and then to C? They would be biochemical experiments not cancer experiments. But if I wish to argue (in an article or grant application) that the experiments are relevant to cancer (perhaps because the sequence of reactions is disturbed in cancer) I could refer to them as cancer-related experiments.

Adding related (and other words) when not required, devalues its meaning when it is required. And scientific thought and argument requires as much precision as possible in the use of words.