You're explaining accuracy vs precision, which I get. The answer actually was: Yes, there's only one instrument. So yes, you can't average out systemic biases.

You're explaining accuracy vs precision, which I get. The answer actually was: Yes, there's only one instrument. So yes, you can't average out systemic biases. So yes, I guess you can say something about "We measure eccentricity zero with 1 part in 1E+17, which is really precise, but you'll just have to trust us it's also accurate." Anyway, we know what everyone meant.