Reconstruction of Reflector Surface Deformations using Back-Projection

One of the primary reconstruction techniques of Classical Tomography incorporates theBack-Projection algorithm. The proposed verification experiment includes a flat reflector fed by a pyramidal horn of a typical gain of 15 dB, and a Near-Field (NF) Open Ended Wave Guide (OEWG). Two hemispherical deformations i.e. dings are made on the reflector. Using Projection Slice Theorem, the Far-Field (FF) radiation pattern is mapped on to the reflector aperture surface. The key objective of the experiment is to determine the exact location of the dings. Using the NF data of the original flat reflector and the deformed reflector, the differential field amplitude and phase values are extracted. The surface deformations are revealed using the difference between two back projected slices. An 8'X8' vertical planar NF scanner is used to obtain the reflector measurements. Both the horn and thr OEWG operate between 8.2 GHz - 12.4 GHz.