Rotational Raman scattering of light from the second harmonic of a Nd:
YAG laser is used to measure atmospheric temperature at altitudes of 3
to 20 km. The method relies on taking the ratio of light passed by tw
o filters that differ slightly in their passbands, and is therefore in
sensitive to variations in atmospheric transmission. The calibration o
f the experiment relies on only spectroscopic measurements and not on
normalizing to nearby radiosondes, as has been the previous practice w
ith this kind of experiment. Comparisons with radiosonde profiles show
excellent agreement to within the precision of the measurements and t
he variability of the atmosphere. The main application of the experime
nt lies in its ability to measure a time series of temperature profile
s with good height resolution throughout a night. Examples of such ser
ies that show the passage of a tropopause fold above the lidar are pre
sented.