function X=kernel_VAD(azimuth,nvad)
[na,nr]=size(azimuth);
allowedval=[3,5,7];
if ~(nvad==allowedval)
    disp('Please select the number of parameters more carefully')
    stop
end
X(:,1)=ones(length(azimuth),1);
X(:,2)=sind(azimuth);
X(:,3)=cosd(azimuth);
if nvad>3
    X(:,4)=sind(2*azimuth);
    X(:,5)=cosd(2*azimuth);
end
if nvad>5
    X(:,6)=sind(3*azimuth);
    X(:,7)=cosd(3*azimuth);
end
return
