Figure 2. Isopleths for dose rate (top) and fluence rate (bottom) as function of \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\dot{Q}}/u\) \end{document} vs. h. The results are shown for A, C and F stability at a downwind distance of 500 m and at ground level. The full curves correspond to a detector placed below the plume centerline (y₀ = 0), whereas the dashed curves correspond to a detector placed at a crosswind distance of 300 m. From: Kalman filtration of radiation monitoring data from atmospheric dispersion of radioactive materials Radiat Prot Dosimetry. 2004;111(3):257-269. doi:10.1093/rpd/nch339 Radiat Prot Dosimetry | Radiation Protection Dosimetry Vol. 111, No. 3 © Oxford University Press 2004; all rights reserved

Figure 1. Horizontal plume and receptor coordinates. From: Kalman filtration of radiation monitoring data from atmospheric dispersion of radioactive materials Radiat Prot Dosimetry. 2004;111(3):257-269. doi:10.1093/rpd/nch339 Radiat Prot Dosimetry | Radiation Protection Dosimetry Vol. 111, No. 3 © Oxford University Press 2004; all rights reserved

Figure 7. Schematic drawing of the experimental setup Figure 7. Schematic drawing of the experimental setup. ⁴¹Ar is emitted from the stack (S) and the primary photon fluence rate from ⁴¹Ar decay is measured by detectors A through D. From: Kalman filtration of radiation monitoring data from atmospheric dispersion of radioactive materials Radiat Prot Dosimetry. 2004;111(3):257-269. doi:10.1093/rpd/nch339 Radiat Prot Dosimetry | Radiation Protection Dosimetry Vol. 111, No. 3 © Oxford University Press 2004; all rights reserved

Figure 4. Simulated and Kalman filtered state variables, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\hat{X}}_{t{\vert}t}\) \end{document} (left column). The solid black curves show the simulated variables, whereas the gray dashed and dot-dash lines show the Kalman filtered parameters using setup 1 (detectors 1–4) and setup 2 (detectors 3–6), respectively. The associated standard deviations, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\surd}\left({\Sigma}_{t{\vert}t}^{xx}\right)_{ii}\) \end{document}, are shown in the right column. From: Kalman filtration of radiation monitoring data from atmospheric dispersion of radioactive materials Radiat Prot Dosimetry. 2004;111(3):257-269. doi:10.1093/rpd/nch339 Radiat Prot Dosimetry | Radiation Protection Dosimetry Vol. 111, No. 3 © Oxford University Press 2004; all rights reserved

Figure 5. Simulated dose rate and wind direction measurements for setup 1 (left column) and setup 2 (right column). The solid curves show the simulated data whereas the dashed lines show the filter-predicted values \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\hat{Y}}_{t{\vert}t{-}1}\) \end{document}. From: Kalman filtration of radiation monitoring data from atmospheric dispersion of radioactive materials Radiat Prot Dosimetry. 2004;111(3):257-269. doi:10.1093/rpd/nch339 Radiat Prot Dosimetry | Radiation Protection Dosimetry Vol. 111, No. 3 © Oxford University Press 2004; all rights reserved

Figure 3. The simulation setup Figure 3. The simulation setup. ‘S’ indicates the stack position while ‘1–6’ denote the six detectors. From: Kalman filtration of radiation monitoring data from atmospheric dispersion of radioactive materials Radiat Prot Dosimetry. 2004;111(3):257-269. doi:10.1093/rpd/nch339 Radiat Prot Dosimetry | Radiation Protection Dosimetry Vol. 111, No. 3 © Oxford University Press 2004; all rights reserved

Figure 6. Parameter correlations calculated from the a posteriori error covariance matrix, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\Sigma}_{t{\vert}t}^{xx}\) \end{document}. The dashed and dot-dashed curves show the results for setup 1 and setup 2, respectively. From: Kalman filtration of radiation monitoring data from atmospheric dispersion of radioactive materials Radiat Prot Dosimetry. 2004;111(3):257-269. doi:10.1093/rpd/nch339 Radiat Prot Dosimetry | Radiation Protection Dosimetry Vol. 111, No. 3 © Oxford University Press 2004; all rights reserved

Figure 8. The solid curves show the fluence rate measurements obtained by the gamma detectors A–D and the wind direction measurements, whereas the dashed curves show the Kalman filter predictions, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\hat{Y}}_{t{\vert}t{-}1}\) \end{document}. From: Kalman filtration of radiation monitoring data from atmospheric dispersion of radioactive materials Radiat Prot Dosimetry. 2004;111(3):257-269. doi:10.1093/rpd/nch339 Radiat Prot Dosimetry | Radiation Protection Dosimetry Vol. 111, No. 3 © Oxford University Press 2004; all rights reserved

Figure 9. The Kalman filtered state variables (left) and associated standard deviations (right). The solid curves show measured values, whereas the dashed curves are the Kalman filter estimates. The Lidar estimates of h at the downwind distance of the detectors (∼200 m) are obtained by linear interpolation between the release height (stack height) and the Lidar measured plume height at ∼400 m from the release point. From: Kalman filtration of radiation monitoring data from atmospheric dispersion of radioactive materials Radiat Prot Dosimetry. 2004;111(3):257-269. doi:10.1093/rpd/nch339 Radiat Prot Dosimetry | Radiation Protection Dosimetry Vol. 111, No. 3 © Oxford University Press 2004; all rights reserved