And they also subjected it to a technique called reflection-mode Fourier-transform infrared spectroscopy.

他们还对其进行了一种称为反射模式傅换红外光谱技术。

Basically, anytime a signal is processed, there's a good chance that a Fast Fourier Transform is involved.

基本上， 每当处理信号时，很有可涉及快速傅换。

Instead, you have to perform something called a Discreet Fourier Transform.

相反，您必须执行称为离散傅换。

And those of you who know about fourier transforms and the FFT algorithm, might see where this is going.

那些了解傅换和 FFT 算法人可会明白这是怎么回事。

To complete one discrete Fourier transform requires multiplying N data points by N different frequency waves.

要完成一次离散傅换，需要将 N 个数据点乘以 N 个不同频率波。

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频率，这意味着他们需要进行傅换。

And one of the distinguishing features of a Discreet Fourier Transform is that the frequency spectrum is also discreet and finite.

离散傅换显着特征之一是频谱也是离散且有限。

And there's also a really excellent video on the channel reducible, talking about the fast fourier transform, which is an algorithm for computing these more quickly.

还有一个关于通道可简化非常出色视频，谈论快速傅换，这是一种用于更快地计算这些算法。

The real obstacle to detecting underground explosions wasn't the accuracy of the seismometers, it was the vast amounts of computation required to Fourier transform the seismometer signals.

探测地下爆炸真正障碍不是地震仪精度，而是对地震仪信号进行傅换所需大量计算。

Now, we can say, whenever you're given two long lists of numbers and you want to take their convolution, first, compute the fast fourier transform of each one of them.

现在，我们可以说， 每当给定两个一长串数字并且想要对其进行卷积时，首先计算每个数字快速傅换。

Physically, this has the effect that when a certain frequency persists for a long time, then the magnitude of the Fourier transform at that frequency is scaled up more and more.

从物理上讲， 这会产生这样效果：当某个频率持续很长时间时，该频率处傅换幅度会越来越大。

Filtering that out, by just smushing the spike down, what you'd be looking at is the Fourier transform of a sound that's just like your recording, only without that high frequency.

通过将尖峰压扁， 将其过滤掉，您将看到声音傅换， 就像您录音一样，只是没有高频。

So on your computer, most of the images will be saved in this form as a two dimensional Fast Fourier Transform and then when you wanna look at the picture again, the computer simply inverts the transform.

因此，在您计算机上， 大多数图像将以二维快速傅换形式保存， 然后当您想再次查看图片时，计算机只需反转换即可。