Top: The fiducial calibration of the spectrograph, i.e., the mean line positions for each line throughout the epoch of stability. The following 3 × 3 grid of plots shows the first nine principal components constructed using LFC lines. These principal components represent the basis vectors along which the calibration of the spectrograph can deviate from the fiducial calibration. For each principal component, or basis vector, each calibration line is plotted according to its echelle order and x-pixel and colored by the value of the basis vector for that line. Principal components beyond the sixth one steadily become more dominated by noise.