=== Examining the Near Fields in Time and Frequency Domains ===
EM.Tempo's FDTD time marching loop computes all the six electric and magnetic field components at every Yee cell of your structure's mesh at every time step. This amounts to a formidable amount of data that is computationally very inefficient to store. Instead, you can instruct EM.Tempo to save a small potion of these data for visualization and plotting purposes. In EM.TempoUsing a '''Field Probe''' at a specified point, you can visualize record the near fields at a specific frequency in a specific plane of the computational time-domain. At field component over the end of an entire FDTD simulation, all the loop. The time -domain electric and magnetic field values are available at all mesh nodes. These temporal quantities results are also transformed into to the frequency domain within the specified bandwidth using a discrete Fourier transforms to calculate the electric and magnetic fields on a specified sensor planetransform (DFT).
[[Image:Info_icon.png|40px]] Click here to learn more about '''[[Data_Visualization_and_Processing#Probing_Fields_in_Time_and_Frequency_Domains | Field Probes]]'''.
In EM.Tempo, you can visualize the near fields at a specific frequency in a specific plane of the computational domain. To do so, you need to define a '''Field Sensor''' observable. EM.Tempo's field sensor defines a plane across the entire computational domain parallel to one of the three principal planes. The magnitude and phase of all the six components of the electric and magnetic fields on the mesh grid points on the sensor plane are computed and displayed.
[[Image:Info_icon.png|40px]] Click here to learn more about '''[[Data_Visualization_and_Processing#Visualizing_3D_Near-Field_Maps | Visualizing 3D Near Field Maps]]'''.