Effective time averaging of multiplexed measurements: A critical analysis
Effective time averaging of multiplexed measurements: A critical analysis
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DOI：
10.1021/ac011153n
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发表时间：
2002-03-15
影响因子：
7.4
通讯作者：
Levin, IW
中科院分区：
文献类型：
--
作者：
Bhargava, R;Levin, IW
信号的多路复用和时间平均是许多分析测量系统中应用的有效降噪协议。这些协议的功效可能会因随机出现的高幅度噪声而降低，这些噪声不符合数据集中所有其他测量的噪声统计分布。这种高幅度的噪声，这可能有一个微不足道的概率发生一个单一的测量，几乎肯定会影响数据收集的多通道，多路复用的方式，如傅里叶变换红外（FT-IR）光谱成像采用焦平面阵列检测器。为了恢复时间平均的优势，在这些情况下，我们提出了一个一般的coaddition方法，使用两个统计措施，平均值和中位数的合奏测量的信号，以获得更好的估计比单独的时间平均估计的真实信号。这种方法，称为中值滤波时间平均，被证明是一个有效的傅立叶变换红外成像数据的噪声去除程序。从理论上研究了时间平均和多路复用的噪声去除的影响，并证明了从人体皮肤活检获得的高光谱红外显微光谱成像数据，通过使用一个快速的数据采集程序。
Multiplexing and time averaging of signal are effective noise reduction protocols applied in many analytical measurement systems. The efficacy of these protocols may be reduced by random occurrences of high-magnitude noise that do not conform to the statistical distribution of noise for all other measurements in the data set. This high-magnitude noise, which may have an insignificant probability of occurrence for a single measurement, almost certainly affects data collected in a multichannel, multiplexed modality, such as Fourier transform infrared (FT-IR) spectroscopic imaging employing focal plane array detectors. To recover time-averaging advantages in these cases, we present a general coaddition method that uses two statistical measures, the mean and median of the ensemble of measurements of a signal, to obtain a better estimate of the true signal than that estimated by time averaging alone. This method, termed median filtered time averaging, is shown to be an effective noise removal procedure for FT-IR imaging data. The effects of noise removal on time averaging and multiplexing are examined theoretically and are demonstrated for hyperspectral infrared microspectroscopic imaging data obtained from human skin biopsies by using a rapid data acquisition procedure.