A fugitive gas detection system includes an inertial measurement assembly that measures a change in position of the inlet of a gas analyzer and applies a time slip to concentration data detected by an analyzer to generate a time series of the concentration of the gas in three-dimensional space. Applying statistical methods, the relative location of the source of the fugitive gas can be established from the time series. Additionally, in some embodiments, the data may be interpolated to establish a map of a plume of the fugitive gas.