This software has been developed by David C. Jenn. POFACETS operates on Physical Optics (PO) approximation for predicting the RCSs of complex objects. It utilizes the scientific computational features of MATLAB and its graphical-user-interface (GUI) functions to provide an efficient calculation of RCS. In this study, we use the latest and updated version (4.2 released in 2015) of POFACETS. The latest version improved computational speed and accuracy.
POFACETS GUI and its Capabilities
POFACETS approximates scattering objects by arrays of triangles (facets) and uses superposition to compute the total RCS of the object. Its GUI consists of five modules: Design Model Manually, Design Model Graphically, Calculate Monostatic RCS, Calculate Bistatic RCS and Utilities as shown in Fig.3.8. POFACETS operates in two graphical modes, i:e: Design Model
Manually and Design Model Graphically. By clicking Design Model Manually tab, a new window will appear where a user can create the geometry of the target and can edit previously designed models. A user can load and merge standard models easily with the help of design Mode Graphically option. POFACETS has a built-in library of common geometrical shapes, that are readily available for the users. 3D model of an object can be rotated, scaled, zoomed-in and zoomed-out in the designing mode. POFACETS has an ability to calculate monostatic or bistatic RCS of the object for the parameters specified by the user and displays plots for its model geometry and RCS.Calculate Bistatic RCS tab GUI display is depicted in Fig. 3.9. To find RCS of an object, a user will first upload the object file by clicking theLoad File button. In incident angle dialog box, the user can specify incident angles fields for θ and φ. Observation or bistatic angle range can be set with feasible increment. By default, Observation Angle range is set from 0◦ to 360◦. By selecting suitable values in Surface Roughness fields, RCS of an object with the desired material can be simulated. With the help of built-in material library, users can set the surface resistivity for their objects. InSurface Roughness, users can specify roughness parameters, i:e:, correlation distance and standard deviation for an object. In Computational Parameter dialog box, a user can specify incident polarization, operating frequency in GHz, and Taylor series. We can easily set a mode of polarization for the incident angle, at incident polarization field Theta-TM polarization corresponds to vertical polarization, while Phi-TM polarization corresponds to horizontal polarization. For
* Copyright || Characterization of Spatial Reflection Coefficient for Ground-to-Aircraft and Satellite-to-Aircraft Communication Links || Master Thesis by Abid Jamal || Capital University of Science and Technology Islamabad || Contact with Author
more accurate results, users can increase the number of terms in Taylor series field. As an increase in the number of terms reduces the computational speed; therefore, there is a trade-off between time and accuracy. Before going to click on Calculate RCS button, there are two buttons available for users in the Computational Parameter dialogue box, i:e: Show 3D Display and Show Polargraph Graph. This will display the linear simulated RCS graph if none of the buttons have been selected. Under utility tab, more options including Import file, export file, and change in the material database. Moreover, users can import AutoCAD (.STL) file to POFACETS with the help of Utility tab.