This Research Highlight showcases the two Research Papers entitled, A
precise photometric ratio via laser excitation of the sodium layer – I.
One-photon excitation using 342.78 nm light,
https://doi.org/10.1093/mnras/stab1621 and A precise photometric ratio
via laser excitation of the sodium layer – II. Two-photon excitation
using lasers detuned from 589.16 nm and 819.71 nm resonances,
https://doi.org/10.1093/mnras/stab1619.