The auto-spectrum is attached to linear phase, the amplitude-frequency drawing is got according to the arithmetic of bi-spectrum, then the equivalent is educed, the conversion relation is attained.

• 该方法通过对自谱添加线性相位，根据双谱的数值估计算法计算获得双谱在三维空间的幅频图，通过推导双谱与自谱估计算法之间的等价关系以及所得的幅频图来实现两者之间的相互转换。