Abr t ra6Three m o t h o d s of remote air pollution detection-Raman bodncattering, resonance backscattering, and resonance absoWh+a n discussed and compared. Theoretical expressions are derived for the minimum detectable pollutant concentration, and in each case the depth resolution and the problems of interference, pump depletion, and background noise are discussed. A brief discussion of possible l o u r sources is included, numerical examples of the dehdabilities based on prescnt technology are given. Tho atmospheric transparency limits the useful range to a few kilometers for the Raman and resonance backscattering schemes. For the resonance absorption technique the useful mnge can be as gnat CH 50 kilometers.