Cecil Moore wrote:
"But the Method Of Moments used by NEC for antenna radiation patterns
calculates the interference at a point in space based on radiation from
different elementary dipole sections of the antenna."

Completely logical and it works. Interference or vector sum?

Terman illustrates radiation from an elementary doublet (dipole) , and
it is mostly at right angles to the antenna axis, on page 865 of his
1955 opus. On page 866 he shows an actual antenna consisting of numerous
elementary doublets and on page 867 he says:
"The result is that the fields radiated from different elementary
sections of a long wire add vectorially to give a sum that depends on
direction."

Kraus devotes Chapter 14 in the 3rd edition of "Antennas" to: "The
Cylindrical Antenna and the Moment Method (MM)."

Best regards, Richard Harrison, KB5WZI