to RV sensitivity of 1.4 pixels (1.4 $\textrm{kms}^{-1}$). In other words, angular uncertainty of 0.01 $^\circ$ in placing of the grating would result in a residual shift of 1.4 pixels. These effects should be carefully accounted for to improve RV precision. The matching of observations with Zemax model and estimating the positions of the optical components and bringing them to a known reference is intended to accomplish this goal.

  **Component**   **Perturbation**   **Pixel shift ($ \textrm{kms}^{-1} $)**
  --------------- ------------------ -----------------------------------------
  Collimator      Tilt $X$ (0.01)    0.6 to -0.8
  Collimator      Tilt $Y$ (0.01)    -16.95 to -18
  Feed mirror     Tilt $X$ (0.01)    0.15 to -0.20
  Feed mirror     Tilt $Y$ (0.01)    -0.735 to -0.855
  Grating         Tilt $X$ (0.01)    1.0 to -0.6
  Grating         Tilt $Y$ (0.01)    21.8 to 20.4
  Grating         Tilt $Z$ (0.01)    0.6 to -1
  Input Optics    Tilt $X$ (0.01)    0.045 to -0.045
  Input Optics    Tilt $Y$ (0.01)    0.56 to 0
  Prism           Tilt $X$ (0.01)    0.06 to -0.06
  Prism           Tilt $Y$ (0.01)    0.78 to 0.62
  Prism           Tilt $Z$ (0.01)    -9 to -10.05
  Temperature     20+0.5 deg         0.12 to 0
  Pressure        1 + 0.12 Pa        0.48 to -0.08

  :  \[tab:perturbations\] Perturbations applied to the individual component for sensitivity analysis of the spectrograph. After the individual component is 