up to PS1_GPC1_Rotator_Measurements

2008.09.15

i've been trying to understand the effects I am seeing in the rotator sequences from 2008.08.27 which I wrote about on friday.

I was not happy with the fits I had to the sequences. I found a minor bug and that improved things a bit, but there were still significant residuals. I decided to plot the residuals. Attached are pairs of plots for each altitude set (30,50,70). Notice the clear 2*POSANGLE term in the residual, which scales with the zenith distance. I'm not fitting for a 2*POSANGLE term, and I'm not sure I see what that corresponds to. any ideas?

fyi, i've also attached the data files with the measured boresite offset and the POSANGLE values for each sequences. Below are my fits:

Xo,Yo : center of the ellipse RX, RY : major and minor axes of the ellipse P0 : position angle of the ellipse in radians T0 : phase lag between POSANGLE and the major axis.

the fitted ellipse has the form:

X = Xo + RX*cos(PA-T0)*cos(P0) + RY*sin(PA-T0)*sin(P0) Y = Yo + RY*sin(PA-T0)*cos(P0) - RX*cos(PA-T0)*sin(P0)

==> rotseq.30.pars <== # fitted values: Xo: 45.276222 Yo: -9.302365 RX: 145.009399 RY: 67.481323 P0: 0.646367 T0: 0.357436

==> rotseq.50.pars <== # fitted values: Xo: 21.140253 Yo: -14.027387 RX: 108.704620 RY: 59.530045 P0: 0.587284 T0: 0.475980

==> rotseq.70.pars <== # fitted values: Xo: 10.799451 Yo: -14.946221 RX: 75.923729 RY: 53.394173 P0: 1.152103 T0: 0.182733

aloha gene