And you have the discreet Fourier transform of this really simple signal.

你可以对这个非常简单的信号进行离散傅里叶变换。

They needed to know how much of different frequencies were present which meant they needed to take a Fourier transform.

他们需要知道存在多少不同的频率，这意味着他们需要进行傅立叶变换。

A Fourier transform is a way of decomposing a signal into pure sine waves, each with its own amplitude and frequency that add to make it up.

傅里叶变换是一种将信号分解为纯正弦波的方法，每个正弦波都有自己的振幅和频率， 相加而成。