## PointingModelOffsets » History » Version 24

*Lucas Beaufore, 08/08/2013 11:46 AM *

1 | 1 | Lucas Beaufore | h1. Pointing Model Offsets |
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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 | 6 | Lucas Beaufore | |

17 | 18 | Lucas Beaufore | The following plots show how adding the trim correction removes the correlation between trim values and the correspoding offsets. The |

18 | 18 | Lucas Beaufore | colors correspond to exposure IDs, approximately time, to help distinguish between exposure sets. |

19 | 1 | Lucas Beaufore | |

20 | 17 | Lucas Beaufore | RA offset corrected with trim_dx value: |

21 | 1 | Lucas Beaufore | |

22 | 19 | Lucas Beaufore | Red = Uncorrected |

23 | 19 | Lucas Beaufore | Blue = Corrected with trim_dx |

24 | 20 | Lucas Beaufore | |!{width:100%}color_ra_correction.png!| |

25 | 1 | Lucas Beaufore | |

26 | 1 | Lucas Beaufore | Declination offset corrected with trim_dy value: |

27 | 17 | Lucas Beaufore | |

28 | 19 | Lucas Beaufore | Red = Uncorrected |

29 | 21 | Lucas Beaufore | Blue = Corrected with trim_dy |

30 | 20 | Lucas Beaufore | |!{width:100%}color_dec_correction.png!| |

31 | 17 | Lucas Beaufore | |

32 | 1 | Lucas Beaufore | |

33 | 1 | Lucas Beaufore | By applying trim corrections, the offsets should no longer include the part of the offset due to hexapod corrections. |

34 | 18 | Lucas Beaufore | As can be seen, adding the correction makes each set of four data points taken in the same position much more horizontal, removing correlation with trim values. |

35 | 11 | Lucas Beaufore | |

36 | 17 | Lucas Beaufore | After applying the correction, the offsets can then be reexamined for correlations with the telescopes position. The plots below illustrate the relations. |

37 | 11 | Lucas Beaufore | |

38 | 14 | Lucas Beaufore | The following two plots show the Declination offsets plotted against the declination of the telescope. The color scale shows the HA of the telescope. |

39 | 15 | Lucas Beaufore | |

40 | 17 | Lucas Beaufore | No correction, correction added |

41 | 17 | Lucas Beaufore | |!{width:100%}dec_teldec_ha.png! |!{width:100%}dec_corrected_teldec_ha.png! | |

42 | 13 | Lucas Beaufore | |

43 | 16 | Lucas Beaufore | |

44 | 12 | Lucas Beaufore | The following two plots show the RA offsets plotted against the declination of the telescope. The color scale shows the HA of the telescope. |

45 | 12 | Lucas Beaufore | |

46 | 17 | Lucas Beaufore | No correction, correction added |

47 | 17 | Lucas Beaufore | |!{width:100%}ra_teldec_ha.png! |!{width:100%}ra_corrected_teldec_ha.png! | |

48 | 24 | Lucas Beaufore | |

49 | 24 | Lucas Beaufore | |_.id |_.telra |_.ha |_.teldec |_.tel_el |_.az |_.hexapod_x |_.telescope_lut_dx |_.bcam_dx |_.hexapod_y |_.telescope_lut_dy |_.bcam_dy |_.object |

50 | 24 | Lucas Beaufore | |222420 |339.005983 |-44.403458 |-75.067998 |40.19 |166.25 |-1140.67 |-1140.67306785 |581.887 |-444.415 |-444.424680399 |3582.832 |Regression Test: HA -3 dec -75 |

51 | 24 | Lucas Beaufore | |222421 |339.005954 |-44.248792 |-75.067609 |40.23 |166.29 |-1100.7 |-1100.70443035 |528.046 |-408.148 |-408.169810085 |3554.484 |Regression Test: HA -3 dec -75 |

52 | 24 | Lucas Beaufore | |222422 |339.005954 |-44.002542 |-75.067609 |40.28 |166.34 |-1087.59 |-1087.56366465 |542.976 |-396.458 |-396.43149795 |3569.16 |Regression Test: HA -3 dec -75 |

53 | 24 | Lucas Beaufore | |222423 |339.005983 |-43.760417 |-75.067637 |40.33 |166.39 |-1075.045 |-1075.04353353 |493.232 |-385.27 |-385.266305108 |3530.39 |Regression Test: HA -3 dec -75 |

54 | 24 | Lucas Beaufore | |222424 |325.755733 |-29.903875 |-75.060498 |42.81 |169.84 |-343.927 |-343.919835158 |-3.504 |238.474 |238.471010059 |3375.81 |Regression Test: HA -2 dec -75 |

55 | 24 | Lucas Beaufore | |222425 |325.755733 |-29.745167 |-75.059942 |42.83 |169.89 |-326.932 |-326.919643698 |-22.494 |252.725 |252.717421599 |3387.304 |Regression Test: HA -2 dec -75 |

56 | 24 | Lucas Beaufore | |222426 |325.755779 |-29.494625 |-75.059942 |42.87 |169.96 |-313.278 |-313.271965285 |-34.88 |263.833 |263.837042061 |3382.333 |Regression Test: HA -2 dec -75 |

57 | 24 | Lucas Beaufore | |222427 |325.755733 |-29.252458 |-75.059942 |42.91 |170.03 |-299.873 |-299.86994067 |-53.506 |274.747 |274.741591957 |3359.672 |Regression Test: HA -2 dec -75 |