Constructed pressure-temperature profiles, which are used to create synthetic transmission spectra for our test cases. Temperature (in K) is shown on the x-axis and pressure (in bar) on the y-axis. The (p. T)-pairs (filled markers) are log-uniformly distributed in the pressure regime of the atmosphere. The shapes of the two profiles characterise a simpler, purely positive temperate lapse rate (solid line) and a more complex structure including a temperature inversion point (dashed line). We note that the (p, T)-pair at p = 10⁻⁵ bar is the same for both cases.