GMT PSSn calculator

PSSn —

WFE RMS — nm exit pupil, all modes

Surface RMS — nm per segment, all modes

Modes applied —

Segment surface figure error

Segment surface figure error map

− x / R − y / R

SFE [nm]

Segment coordinate systems of M1 and M2: each segment's unit
vectors, in a front view of the 7 segments and a side view
through the mirror. — Where the disc lands. The map above is one segment's unit disc, drawn in that segment's own frame — so to place a feature on segment k, turn the disc onto segment k's x̂, ŷ here. M1's frames are the pupil frame clocked by −60° per segment; M2's carry the same clocking but are left-handed, ŷ flipped. M2's segments are numbered opposite M1's because the beam crosses between the two mirrors.

Exit-pupil wavefront error

Exit-pupil wavefront error map

− x [m] − y [m]

WFE [nm]

PSSn loss per Zernike mode

Each mode applied to all 7 segments on its own. Loss = (1 − PSSn) in parts per million.

Table view

Zernike	RMS [nm]	PSSn	WFE RMS [nm]	Loss [ppm]