    function [uTotRX, uIncRX, uScaRX] = uSca(uTotRX,uIncRX,frequencyId)
    % Compute the scattered field uScaRX at receivers positions:

    % Conjugate the fields to adapt from time dependence exp(iwt) to exp(-iwt):
    uTotRX   = conj(uTotRX);
    uIncRX   = conj(uIncRX);

    % FmeasDelta = uScaRX = uTotRX - uIncRX:
    uTotRX = uTotRX(:,:,frequencyId);
    uIncRX = uIncRX(:,:,frequencyId);

    %
    uScaRX = uTotRX - uIncRX; % uScaRX = uTotRX - uIncRX
    end