How to create an ISO 8606 disturbance profile?

Hello!

I am trying to create an ISO 8606 class D disturbance profile. I tried to follow the code described here but I am getting a disturbance with a magnitude of 0.2 meters. Many of the papers I have seen that utilize this standard have magnitudes around 0.02 meters so I wasn't sure if I was doing something wrong. I have dropped my code below. Does anyone have any experience with creating this profile? Thank you!

function [dist, ref, hx] = ISO8606TypeD(t)

delay=.4;  %there is a .4s gap between when the front wheel hits the bump and the second wheel hits it
deltaIndex = t(2)-t(1);
iP = 100;

hx = generateProfile(t, iP);

hx = hx - hx(1);

dist(1,:) = [hx zeros(1,iP)];
dist(2,:) = [zeros(1,delay/deltaIndex) hx zeros(1,iP-delay/deltaIndex)];

ref = zeros(12, length(t));

figure(2)
hold on
plot(t,dist(1,:))
plot(t,dist(2,:))
title('ISO8606 Disturbance Profile');
xlabel('Time [s]');
ylabel('Disturbance [m]')

end

function hx = generateProfile(t, iP)
vel=10; % car velocity [m/s]
N  = length(t) - iP;    %  Number of data points
L  = t(end)*vel;      % Length Of Road Profile (m)
k = 6;                  % A = 3, B = 4, C = 5, D = 6, E = 7, F = 8, G = 9
B  = L/N;               % Sampling Interval (m)
dn = 1/L;               % Frequency Band
n0 = 0.1;               % Spatial Frequency (cycles/m)
n  = dn : dn : N*dn;    % Spatial Frequency Band
phi =  2*pi*rand(size(n));              % Random Phase Angle
Amp1 = sqrt(dn)*(2^k)*(1e-3)*(n0./n);   % Amplitude for Road  Class A-B
x = 0:B:L-B;            % Abscissa Variable from 0 to L

hx = zeros(size(x));
for i=1:length(x)
    hx(i) = sum(Amp1.*cos(2*pi*n*x(i)+ phi));
end

[q , C] = psd_1D(hx, B, 'x');
f = q / (2*pi);         % spatial frequency
PSD = 2 * pi * C;       % power spectrum

figure(1)
loglog(f,PSD)
title('Power Spectral Density');
xlabel('Frequency (Hz)');
ylabel('PSD (m^3)');

end