Improved source term description in Eulerian models in ARGOS

Atmospheric dispersion models can be formulated and implemented in two different ways, e.g. as Eulerian and Lagrangian models. These implementations have both advantages and disadvantages concerning numerical requirements and accuracy. A combination of both implementations - a hybrid approach is also possible and, we show some improvement to a pure approach, when using this method. In many practical cases of measured radioactive air concentrations, the source time and location is not known. Inverse modelling can be used to help identifying the source. Using a simplified footprint analysis, it is even possible to combine the information from several measurement stations to get an improved picture over possible sources from an atmospheric point of view.