An implicit method is employed in solving diffusion term and projection term, such as Gauss-Seidel iteration method, Fast Fourier Transform.
在求解扩散项和投影项时，采用隐式的求解方法，例如高斯—塞德尔迭代法、快速傅里叶变换。
2
As a result, with phase unwrapping technique based on Fourier transform, any cross section projection could conveniently be worked out from the Moiré deflectogram of rocket exhausted plumes.