The feedhorn is located directly above the center of the central disc reflector. Actually, this is only the most rudimentary beginning of the simulation which sums the contributions from all these zones at the feedhorn. The groundplane is NOT included in this simulation. All dimensions are in meters, angles in radians, except for DG which is the off-axis pointer, and is in degrees. R0 is feedhorn height above the bullseye, and is also approximate bullseye outer diameter.
LA is wavelength.
A is the computed amplitude of the received signal. Rotation of AD through Pi radians is sufficient, as continued rotation only duplicates. This program was written and debugged on an Apple II computer in Apple Basic. This was done so that this program could be debugged and presented to the Group within a reasonable time. We suspect ET will come before the Apple II finished the simulation above.