Changing coronal hole angle formula?

[imogenagle]

The average angle that the coronal hole is subjected to uses the Pythagorean formula to calculate the angle. Should we change the formula so that it uses non-Euclidian geometry or is the scale so large that it becomes irrelevant?

[samaloney]

Which coordinate system if you measure the width in HeliographicStonyhurst (HGS) then I don't think you need to do anything, if you measure it in HelioprojectiveCartesian (HPC) then I don't think you need to do anything either but not sure how useful that measurement is?

[imogenagle]

    """calculate area of CH with minimal projection effects"""

    trupixar = abs(area / np.cos(ang))
    truarcar = trupixar * (dattoarc**2)
    trummar = truarcar * ((6.96e08 / rs) ** 2)

[imogenagle]

I think it should be in heliographic stonyhurst