Left panel: distribution of RMS over final map. RMS taken over a line free range from −50 to −20 km s⁻¹ with a 0.3 km s⁻¹ spectral resolution. Left inset panel: RMS map shows a histogram of the distribution of RMS over the entire map with a peak value of 1.63K. Right panel: distribution of spectrum RMS before map generation with a 0.3 km s⁻¹ spectral resolution. Some pixels have two peaks (V1 and H2) or a trailing tail (V3) in their distribution, indicating a change in RMS performance over the two flight series.