The paper describes a new approach to quantify emissions from area air pollution sources. The approach combines path-integrated concentration data acquired with any path-integrated optical remote sensing (PI-ORS) technique and computed tomography (CT) technique. In this study, and open-path Fourier transform infrared (OP-FTIR) instrument sampled path-integrated concentrations along five radial beam paths, in a vertical plane downwind from an area source. The innovative CT technique, which applies the smooth basis function minimization (SBFM) method to the beam data in conjunction with measured wind data, was used to estimate the total flux from the area source. Results are presented from a field experiment designed for quantifying ammonia and methane emissions before and after a bioactive cover was added to control odors from a hog farm waste lagoon near Jacksonville, NC. This field study provides a new insight to the processes taking place in these facilities. The suggested technologies may provide robust and real-time estimates of gaseous emission fluxes and near-field dispersion parameters for near-ground level area sources.