Groundbased optical imaging observations of the Jovian environment using a 4-in.-aperture telescope have revealed a large cloud of neutral sodium extending out to more than 400 Jovian radii ( RJ) in the planet's equatorial plane. Preliminary analysis of one image, taken on 25 January 1990, has been published. This one image represents a small fraction of the data obtained during our initial observations conducted in November and December 1989 and January 1990 at the McDonald Observatory. The 1989 observational campaign consisted of low-dispersion imaging spectrograph observations, while the 1990 campaign consisted of direct imaging observations. In this work, we present analysis and modeling of our initial data sets, concentrating on such properties as morphology, abundances, source rates and mechanisms, and spatial asymmetries. In addition, a complete description is given of the observational and data reduction techniques employed in these pilot studies of an extended planetary atmosphere.