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

他们还对其进行了种称为反射模式傅立叶变换红外光谱的技术。

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，很有可涉及快速傅立叶变换。

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

相反，您必须执行称为散傅立叶变换的操作。

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

那些了解傅立叶变换和 FFT 算法的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.

要完成散傅立叶变换，需要将 N 个据点乘以 N 个不同频率的波。

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的频率，这意味着他们需要进行傅立叶变换。

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

散傅立叶变换的显着特征是频谱也是散且有限的。

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.

还有个关于通道可简化的非常出色的视频，谈论快速傅立叶变换，这是种用于更快地计算这些的算法。

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.

探测地下爆炸的真正障碍不是地震仪的精度，而是对地震仪信号进行傅立叶变换所需的大量计算。

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， 每当给定两个长串字并且想要对其进行卷积时，首先计算每个字的快速傅立叶变换。

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， 这会产生这样的效果：当某个频率持续很长时间时，该频率处的傅立叶变换的幅度会越来越大。

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，您将看到声音的傅立叶变换， 就像您的录音样，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，在您的计算机上， 大多图像将以二维快速傅立叶变换的形式保存， 然后当您想再查看图片时，计算机只需反转变换即可。