Positive Matrix Factorisation (PMF) is a statistical factor analysis method, based on the law of mass conservation. By analysing measured concentrations at a series of measurement locations, the method first identifies a set of factors which can be taken to represent major emissionsources. Scores on these factors are thenregressed against the concentrations to estimate the contributions from each source.
Soonthornnonda, P. and Christensen, E. (2008). Source apportionment of pollutants and flows of combined sewer wastewater. Water Research Volume 42, Issues 8–9, Pages 1989–1998.