  The composition and distribution of the gas in a protoplanetary disk plays a
key role in shaping the outcome of the planet formation process.
Observationally, the recovery of information such as the emission height and
brightness temperature from interferometric data is often limited by the
imaging processes. To overcome the limitations of image-reconstruction when
analyzing gas emission from interferometric observations, we have introduced a
parametric model to fit the main observable properties of the gaseous disk
component in the visibility plane. This approach is also known as parametric
visibility modeling. We applied our parametric visibility modeling to the gas
brightness distribution of the molecular line emission from 12CO J=3-2 and 13CO
J=3-2 in the disk around MHO 6, a very-low-mass star in the Taurus star-forming
Region. To improve the flux fidelity of our parametric models, we combined
models with different pixel resolution before the computation of their
visibilities, referred to as ``nesting images.'' When we apply our parametric
visibility modeling to MHO 6, with independent fits to the emission from its CO
isopotologues, the models return the same consistent results for the stellar
mass, disk geometry, and central velocity. The surface height and brightness
temperature distribution are also recovered. When compared to other disks, MHO
6 surface height is among the most elevated surfaces, consistent with the
predictions for disks around very-low-mass stars. This work demonstrates the
feasibility of running rapidly iterable parametric visibility models in
moderate resolution and sensitivity interferometric observations. More
importantly, this methodology opens the analysis of disk's gas morphology to
observations where image-based techniques are unable to robustly operate, as in
the case of the compact disk around MHO 6.
