We report a detailed analysis of lidar systems that profile aurorally
excited molecular species in the upper mesosphere and lower thermosphe
re (similar to 80-300 km). Current profiling of this region is perform
ed with incoherent scatter radars that determine the total electron an
d ion concentrations but not the individual species. Studies of the ae
ronomy of the thermosphere requires knowledge of the species present a
nd their relative populations in the different vibrational and rotatio
nal states. We review the spectroscopy of nitrogen to determine an opt
imized Lidar system. We combine these results with current auroral obs
ervations and models to determine the performance of an actual lidar s
ystem. The study shows that such systems can provide high-resolution (
1 km, 100 s) measurements of these species with current laser technolo
gy. (C) 1997 Optical Society of America.