Observations are not easy, what an object should be and what it looks like in data are always quite different. There is no perfect technique and telescope, we have to do something to restore truths, which includes telescope calibration. For example, shapes of X-ray spectra can be changed during detection, to calibrate which response and redistribution files need to be calculated by comparing the observed spectra with other telescopes' data. That is what I did for an X-ray telescope.
How can we measure solar wind in high ecliptic latitudes? It is very hard to send a satellite there, and speculation is also difficult because solar wind changes rapidly during propagation. Here come comets! Comets can reach there! The interaction SWCX between comets and solar wind can tell us a lot about solar wind, comets' coma, and even atomic physics. HKU has a great opportunity to launch a satellite to observe SWCX in EUV band. I analysed SWCX for 5 comets in X-ray band and predicted EUV spectra for the satellite design.