H₂O and HO lines observed in comet C/2009 P1 (Garradd) on 22 February 2012. The channel spacing of the 1₁₁–0₀₀ and 2₁₁–2₀₂ H₂O HRS spectra is 120 kHz, corresponding to 0.033 and 0.048 km s^-1, respectively. The WBS spectrum of the 1₁₁–0₀₀ HO line has a spectral resolution of 1 MHz (0.27 km s^-1). The horizontal axis is the Doppler velocity based on the rest frequency of the transition.