We describe at first a review of the techniques used in the area of High Spectral Reso- lution Lidars (HSRL) for studying the aerosol phase function. We present for the first time results from the application of this technique in Extensive Air Showers telescopes atmospheric monitoring systems. We present our progress towards assembling such instrumentation. Using this, we are aiming to in- vestigate the aerosol optical properties in the lower troposphere measuring the scattering cross section as (HSRL) use spectroscopic or inteferometric or other techniques in order to determine the exact components of the scattered light for high accuracy measurements. At such EAS experiments, for determining the aerosol phase function, typically a laser or some pulsed xenon lamp, emits light and the fluorescence detectors re- ceive the light scattered. This light contains mainly two components. The one is due to Mie scattering from aerosols and the other is the Rayleigh scattering due to molecules. In order to distinguish these two components the Rayleigh night has to be used for the rejection of the signal due to molecules. The Rayleigh night is a night with out aerosols. This method is based on the