UV-visible absorption measurement techniques using several horizone viewing directions in addition to the traditional zenith-sky pointing have been recently developed in ground-based remote sensing of atmospheric constituents. The spatial distribution of various trace gases close to the instrument can be derived by combing several viewing directions. Multi-axis differential optical absorption spectroscopy (MAX-DOAS) technique, one of the remote sensing techniques for air quality measurements, uses the scattered sunlight as a light source and measures it at various elevation angles (corresponding to the viewing directions) by sequential scanning with a stepper motor. A MAX-DOAS system developed by GIST/ADEMRC has been applied to measuring trace gases in urban air and plumes of the volcano and fossil fuel power plant in January, May, and October 2004, respectively. MAX-DOAS spectra were analyzed to identify and quantify $SO_2,;NO_2,;BrO,;and;O_4$ (based on Slant Column Densities, SCD) in the urban air, volcanic plume, and fossil fuel power plant utilizing theirs specific structured absorption features in the UV-visible region. Vertical scan through the multiple elevation angles was performed at different directions perpendicular to the plume dispersion to retrieve cross-sectional distribution of $SO_2;or;NO_2$ in the plumes of the volcano and fossil fuel power plant. Based on the estimated cross sections of the plumes the mixing ratios were estimated to 580 $SO_2$ ppbv in the volcanic Plume, and 337 $NO_2;and;227;SO_2$ ppbv in the plume of the fossil fuel power plant, respectively.