In this example the BistaticRCS with a sweep on frequency from 3 GHz to 5 GHz with 3 steps over MoM of spherical chaff is calculated.
Let's create a Chaff Project. Start newFASANT if it's not already open, then go to File > New, and select a Chaff project.
New Projects command
Module selection box
Let's start creating an Spherical Chaff. Go to Chaff > Spherical Chaff and set the values to the following:
- Center: X=0, Y=0, Z=0.
- Radius: R=0.5
- Number of dipoles: 300
- Radius: 3E-4
- Max. Length: 1,5E-2
- Min. Length: 1,5E-2
Spherical Dipole Chaff Menu option
Spherical Chaff parameters and visualization
Let's set the simulation parameters so that a frequency sweep is made. Click on Simulation → Parameters. Then enable Sweep by pressing "Enable Sweep" and set the simulation to make a sweep starting on 3 GHz, up to 5 GHz taking 3 samples, as shown in the following figure. Press Save when done.
Simulation Parameters command
Simulation Parameters panel
Then, the solver settings will be set. Select Solver → Parameters and set the values to the following:
- Solver Method: Method of Moments.
- Conductor Losses: 0 Ω/m.
- Relative Error: 0.01.
- Maximum Number of Iterations: 5000.
Solver Parameters command
Solver Parameters panel
Let's change the RCS Type. Select RCS → Parameters. Set the RCS type to Bistatic and leave all other parameters as they are by default.
RCS Parameters command
RCS Parameters panel
Let's define some far field observation points. Select Output → Observation Directions. Create a phi cut by pressing Add under the Phi Cuts section, and the modify the values in the table. Set the sweeping values as:
- Phi cut: 0.0º
- Initial theta: 0.0º
- Increment: 10.0º
- Samples: 19
Final theta value should be 180º. Press Save when you are done.
Observation Directions command
Observation Directions panel
Select Output → Show 3D Diagram.
Show 3D Diagram option
Since 3D Diagrams increase the time required to simulate the project, you'll be asked to confirm your selection. Press Yes to do so.
Show 3D Diagram question
The case has to be meshed before calculating it. Select "Meshing →Create Mesh" and set the number of planar and curved surfaces divisions to 10. This is a small project, so the default settings for processors can be left. Click on Mesh to mesh the example.
Meshing Parameters command
Meshing Parameters panel
Then, select Calculate → Execute. Set the number of processors to the better value as available for your computer resources, and press Execute for simulating the project. The operation will take a while since multiple frequencies have been selected and a 3D Diagram calculation has been requested.
Execute Parameters command
Execute Parameters panel
Execute Information panel
When the simulation finishes, we can show results. Click on Show Results → Far Field → View Cuts, to show the RCS graphic.
Far Field View Cuts command
Far Filed RCS Graphic
Click on Show Results → Far Field → View Text Files, to show the RCS data file.
Far Field View Text File command
Select the frequency to show and click on OK.
Far Field Text File selection
Result Text File visualization
Click on Show Result → RCS Diagram → View RCS 3D to load the 3D representation of the measurements.
View 3D RCS command
View 3D RCS