Left panel: example of a single detector frame measured by ACS MIR in secondary grating position 12 after processing (orbit 6975, L_s = 40.3°, tangent altitude 13 km). Right panel: associated series of transmission spectra, covering the wavenumber range from 2894 cm⁻¹ (diffraction order 173) to 3239 cm⁻¹ (order 192). The left and right edges of the frame in the spectral dimension, where the signal decreases, are cropped.