From Friday, April 19th (11:00 PM CDT) through Saturday, April 20th (2:00 PM CDT), 2024, ni.com will undergo system upgrades that may result in temporary service interruption.
We appreciate your patience as we improve our online experience.
From Friday, April 19th (11:00 PM CDT) through Saturday, April 20th (2:00 PM CDT), 2024, ni.com will undergo system upgrades that may result in temporary service interruption.
We appreciate your patience as we improve our online experience.
|
基带FFT运算考虑了你设定的频率范围,用额外的元素来显示范围内所有的频点。比如,对下面的数据进行基带FFT运算。
频率范围: 24000 Hz
谱线总数: 800
从上面给定的数字中, NI-DSA 将会通过用频率范围除以谱线总数来计算dF(相临两个频点之差)的值:
dF = 频率范围 / 谱线总数
dF = 24000 / 800 = 30 Hz / bin
返回的数组中的 第一个元素代表信号的直流分量,也就是0Hz处。其他每个数据组都代表了其中的一个DF,直到给出代表频率范围中最高频点的数据组。下面的表格可以帮助解释为什么在返回的数组中会有一个多余的谱线:
数组 | 频率 | |
元素0 | ---> | 0 Hz |
元素1 | ---> | 30 Hz |
元素2 | ---> | 60 Hz |
... | ... | |
... | ... | |
元素800 | ---> | 23970 Hz |
元素801 | ---> | 24000 Hz |
|