secondary_mirror_parameters

Telescope: SSTS-design

Description: Defines the position of the secondary mirror along the optical axis and its shape. The first parameter (\(p_0\)) is the offset of the mirror with respect to the common reference point defined by par:mirror-offset, with positive values indicating that the centre of the primary (assuming it has no central hole) is above the reference point. The secondary mirror looks the other way, i.e. \(p_0\) will usually be negative since in the coordinate frame of the secondary, it is below the common reference point. Apart from that, a parameter \(p_i\) adds a term \(p_i r^{2i}\) to the height of the mirror at radial offset \(r\). A parabolic mirror will have the second parameter (\(p_1\)) at a positive value and all further parameters at 0. A concave secondary, reducing the focal length if placed between the primary and its focus, will have \(p_1 > 0.\). A convex mirror (e.g.~for Cassegrain or Ritchey-Chr’etien optics), enlarging the focal length, will have \(p_1 < 0\).

Parameter Version	Model Version(s)	Value
1.0.0	6.0.0, 5.0.0	310.84 cm, 0.00229358 cm, 2.8273e-08 cm, -2.7689e-12 cm, 8.80066e-17 cm, 3.37315e-21 cm, -1.02973e-25 cm, -6.72882e-30 cm, -3.06437e-34 cm, 3.1718e-38 cm, -3.71217e-43 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm, 0.0 cm