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P.F. Corrector Plate Distortions from Burt Jones

Set up standard coordinates x_t, y_t using

- plate center as tangent point
- refracted coordinates for field center and star positions
- scale of 12.3230 "/mm

x = x_t + alpha * (x_t - x_0) * r^2 + beta * (x_t - x_0) * r^4

y = y_t + alpha * (y_t - y_0) * r^2 + beta * (y_t - y_0) * r^4

where

r^2 = (x_t - x_0)^2 + (y_t - y_0)^2

alpha = 4.489E-7 mm^-2

beta = 1.731E-12 mm^-4

x_0 = 6.399 mm

y_0 = -0.215 mm

Further discussion with Burt Jones suggests that some of this transformation may not be suitable for use with the MOS. Some good references are

Murray, MNRAS

Herbig & Jones, AJ

Back to the MOS home page.

Steve Allen <sla@ucolick.org>