dc.contributor.author Kathirgamanathan, P. dc.contributor.author McKibbin, R. dc.contributor.author McLachlan, R.I. dc.date.accessioned 2013-05-13T00:06:32Z dc.date.available 2013-05-13T00:06:32Z dc.date.issued 2003 dc.identifier.citation Kathirgamanathan, P., McKibbin, R., McLachlan, R.I. (2003), Source release-rate estimation of atmospheric pollution from a non-steady point source - Part 2: Source at an unknown location, Research Letters in the Information and Mathematical Sciences, 5, 85-118 en dc.identifier.issn 1175-2777 dc.identifier.uri http://hdl.handle.net/10179/4415 dc.description.abstract This paper presents an inverse modelling procedure to estimate the location and release rate en of atmospheric pollution. The input to this model requires measured pollution concentration at a minimum of three observation sites on the ground and meteorological conditions such as wind speed and cloud cover. The inverse model is formulated as a least squares minimisation problem coupled with the solution of an advection-diffusion equation for a non-steady point source model. Since the minimisation problem has a combination of linear and non-linear parameters the problem is solved in two steps. Non-linear parameters are found by constructing an iterative procedure using an optimisation routine such as MATLAB’s lsqnonlin and at each iteration, the linear subproblem is solved to estimate the linear parameters. Finding the linear parameters is an ill-posed problem and consequently its solution is extremely sensitive to errors in the data. Tikhonov regularisation, which stabilises the process of the solution, is used to overcome the ill posedness of the problem and the regularisation parameter is estimated using the properties of the non-linear L-curve, linear L-curve and generalised cross validation. Finally, the accuracy of the model is examined by imposing normally-distributed relative noise into concentration data generated by the forward model. dc.language.iso en en dc.publisher Massey University en dc.subject Atmospheric pollution en dc.subject Pollution measurement en dc.subject Pollution release rate en dc.title Source release-rate estimation of atmospheric pollution from a non-steady point source - Part 2: Source at an unknown location en dc.type Article en
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