Observations divided by TPM predictions (ϵ = 1.0; albedo A = 0.10) as a function of wavelengths (and for channel 08 at 11.1 μm also as a function of phase angle in the inserted figures). The measurements are shown as diamond symbols, the scatter within each channel or wavelength is associated to a small but systematic deviation dependent on phase angle. The ECOSTRESS emissivity (calculated as 1-reflectance) spectra for two extreme maria samples (solid lines) and two extreme highland samples (dotted-dashed lines) are shown. All other (maria, transition & highland) samples would fall between these lines. Top: for a low surface roughness (rms 20°). Bottom: using a high roughness (rms 40°) in the TPM. The dotted lines in the phase angle plots are second order fits through the ratios.