Measuring and tracking the gases that vent from an erupting volcano is a project fraught with potential dangers and difficulties. Taking measurements on the ground places researchers in harm's way, as does taking airborne samples. These approaches also may suffer from issues around accurately representing the spatial and temporal shifts in gas emissions rates. As such, satellite-based remote sensing techniques are becoming a preferred way to assess the dispersion and concentrations of various volcanic gases. Devising a functional remote sensing scheme, however, depends on identifying a satellite sensor that can reliably identify the chemical species in question and pick the volcanic emissions out from the background concentrations. Such efforts have so far been successful for only a few volcanic gases: sulfuric acid, hydrochloric acid, and hydrogen sulfide.