Altitude profile with HARPS as obtained from Eq. (1) (method 1). A 10 Å bin is superimposed in light-blue over the full-resolution profile. The profile shows the large bump due to ozone Chappuis band around 6000 Å, the oxygen γ- and B-band at 6300 at 6900 Å  respectively, and also the water-vapour band around 6500 Å. The expected increased of h(λ) in the blue due to Rayleigh is visible as a negative slope between 4000 and 5000 Å. Oxygen and water-vapour absorption spectra at arbitrary scale are shown.