[[Image:ff settings.png|thumb|left|150px|Adding an RCS observable for the Mirage project]]
First, we create an RCS observable with 1 one degree increments in both phi and theta directions. Although increasing the angular resolution of our farfield will significantly increase simulation time, The RCS of electrically large structures tend to have very narrow peaks and nulls, so the resolution is required.
We also create two field sensors -- one with a z-normal underneath the aircraft, and another with an x-normal along the length of the aircraft. The nearfields are not the prime observable for this project, but they may add insight into the simulation, and do not add much overhead to the simulation.
Since we're computing a Radar Cross Section, we also need to add a planewave source. For this example, we will specify a TMz planewave with k = sqrt(2)/2 x - sqrt(2)/2 z, or theta = 135 degrees, phi = 0 degrees.
[[Image:Large struct article mesh detailsettings.pngpng |thumb|left|150px200px|Figure 1: Geometry of Mesh settings used for the periodic unit cell of the dispersive water slab in EM.TempoMirage project.]]
[[Image:Large struct article mesh settingsdetail.png png|thumb|left|150px200px|Figure 1: Geometry of Mesh detail near the periodic unit cell cockpit region of the dispersive water slab in EM.Tempoaircraft.]]
For the mesh, we use the "Fast Run/Low Memory Settings" preset. This will set the minimum mesh rate at 15 cells per lambda, and permits grid adaptation only where necessary. This preset provides slightly less accuracy than the "High Precision Mesh Settings" preset, but results in smaller meshes, and therefore shorter run times.
At 850 MHz, the resulting FDTD mesh is about 270 million cells. With mesh-mode on in [[EM.Cube]], we can visually inspect the mesh.
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