notice how the lines occurs at 0.05 intervals, i dont think it is related to the grids
plotting code if this helps Y is a 401x401 matrix which corresponds to the height in the plot
x = 10:0.05:30;
z = 1:0.005:3;
[X,Z] = ndgrid(x,z);
mesh(X,Z,Y)
xlabel('x'),ylabel('z'),zlabel('height')
axis auto
xlim ([10 12])
