Aerosols impact Earth’s climate system in a variety of processes. However, the mostsignificant process involves the direct perturbation of Earth’s energy budget via particle- radiation interactions as light propagates through the atmosphere. Climate models attempt to quantify the anthropogenic contribution to the climate forcing phenomenon through de- tailed understanding of myriads of atmospheric species. However, large uncertainties persist and have been shown to depend significantly on optical parameters used to characterize atmospheric aerosols within the radiative transfer codes of climate models. In a fifth as- sessment by the Intergovernmental Panel on Climate Change (IPCC), it was shown that significant uncertainties in aerosol optical parameters such as the single scattering albedo (SSA), asymmetry parameter (g), and aerosol optical depth (AOD) resulted in large uncer- tainty in the total aerosol forcing contribution. These uncertainties ultimately contributed significantly to the large uncertainty on the calculated radiative forcing value associated with direct anthropogenic aerosol-radiation interactions. Thus, there is a need to determine highly accurate aerosol optical parameters and prop- erties via improvements in aerosol measurement technologies and retrieval processes. The current work is centered upon the development of an imaging polar nephelometer (I-PN) for measurements of polarized phase functions, the degree of linear polarization, and the asymmetry parameter on a variety of lab generated aerosol particles and ambient aerosols. In this particular work, the phase functions were used to determine the aerosol particle size distribution and real refractive index from lab generated ammonium sulfate, sodium chlo-ride, and squalane particles. Measured phase functions were used to calculate g for the aforementioned aerosol samples. Ambient aerosol measurements were also presented in this work. The development of this instrument adds a directional scattering dimension to our existing light extinction and absorption based retrieval capabilities. The development of this polar nephelometer will help to ensure more complete aerosol optical characterizations and improved classification capabilities with the inclusion of morphological and coating informa- tion in future work.