![fdtd yee cell fdtd yee cell](https://www.researchgate.net/profile/Mohd-Ishak-8/publication/322913707/figure/fig2/AS:589938462560272@1517663698856/The-Yee-cell-Electric-field-components-are-at-the-centers-of-the-cell-edges-and-the_Q320.jpg)
Transfer function between the line integrated density and the phase differenceįig. A diagram for the reconstruction Alorithm 1.įig. The finite-difference time-domain method (FDTD) is the common numerical method studying the GPR wave propagation law in layered structure. The following reconstruction algorithms have been used, but it is difficult to find the self-consistent density due to errors in the numerical simulations and the measurement.įig. Ground penetrating radar (GPR), as a kind of fast, effective, and nondestructive tool, has been widely applied to nondestructive testing of road quality. If the estimated phase difference from 3-D FDTD simulation based on the assumed density deviates a lot from the measured phase difference, it needs to reconstruct the actual density using the simulation results.
#FDTD YEE CELL CODE#
Maxwell equations with the discretization of the currents for 3-D FDTD simulationĪ source code for 1-D FDTD A source code for 3-D FDTD Strategy to reconstruct the density from measurement of phase difference Sketch of Yee cell (the location of electric, magnetic, and current vectors)įig. An example of the electron density reconstructed by the phase difference measured by the interferometerįig. Sketch of the interferometer measurement around a Hall trusterįig. Three-dimensional FDTD simulations that also account for electron collisions and magnetic fields indicate that the departure from the use of the usual simple models is no more than about 15%, well within the limits of uncertainty in the experimental measurements taken within the near field of these plasma sources.įig. One-dimensional plane wave FDTD simulations indicate that plasma non-uniformities along the direction of wave propagation have only a minor effect on the phase shifts estimated from collisionless, non-magnetized wave propagation through a path-length averaged plasma slab. The simulations are intended to address potential issues (collisions, magnetic fields) that may affect the validity of the simple theory used for phase shift determination in the recent measurements of plasma density using microwave interferometry (Cappelli et al 2006 J. The millimetre wave plasma interferometer has been utilized to measure the electron density of plasma non-intrusively. Mark Cappeli present finite difference time domain (FDTD) simulations of millimetre-wave propagation through the near-field plasma plume of low power Hall thrusters. This project was done in the master program at Stanford University. Finite-difference time-domain code for interferometer