Project

General

Profile

PointingModelOffsets » History » Version 4

Lucas Beaufore, 07/12/2013 12:23 PM

1 1 Lucas Beaufore
h1. Pointing Model Offsets
2 1 Lucas Beaufore
3 1 Lucas Beaufore
In order to study the effects the pointing model may have on the offsets, new offsets were calculated with possible corrections from the effects of the hexapod trim values.
4 2 Lucas Beaufore
5 2 Lucas Beaufore
The following histograms show the distribution of the offsets before trim corrections, and with a trim correction of both addition and subtraction.
6 2 Lucas Beaufore
7 2 Lucas Beaufore
8 3 Lucas Beaufore
RA offset with: No correction, addition of a scaled (.0176 arcsec/micron) trim_dy value, subtraction of the scaled trim_dy value
9 3 Lucas Beaufore
10 2 Lucas Beaufore
|!{width:100%}dec_standard.png! |!{width:100%}dec_corrected_y.png! | |!{width:100%}dec_corrected_minus_y.png! |
11 3 Lucas Beaufore
12 3 Lucas Beaufore
Dec offset with: No correction, addition of a scaled (.0176 arcsec/micron) trim_dx value, subtraction of the scaled trim_dx value
13 3 Lucas Beaufore
14 2 Lucas Beaufore
|!{width:100%}ra_standard.png! |!{width:100%}ra_corrected_x.png! | |!{width:100%}ra_corrected_minus_x.png! |
15 4 Lucas Beaufore
16 4 Lucas Beaufore
The effect of the corrections are arguably more visible on a 3D plot. The following show the tweak values and exposure ID values (essentially time, in order to better show the exposure groups)
17 4 Lucas Beaufore
versus the offsets. 
18 4 Lucas Beaufore
19 4 Lucas Beaufore
Declination offsets vs trim_dy (vs expid):
20 4 Lucas Beaufore
21 4 Lucas Beaufore
|!{width:100%}dec_all_corrections_back.png |!{width:100%}dec_all_corrections_side.png! | 
22 4 Lucas Beaufore
23 4 Lucas Beaufore
|!{width:100%}ra_all_corrections_side.png |