Terra MODIS第5波段红外遥感影像条带噪声的探测与校正

Terra MODIS band 5th stripe noise detection and correction using MAP-based algorithm

由于TerraMODIS传感器第5波段（1．230～1．250I,zm）中部分探测元件出现故障，从而导致整幅影像上存在明显的条带噪声。对于地理校正后的MODIS影像数据，其条带噪声的分布并不是完全规则的，还可能存在不连续的现象，加大了对噪声进行处理的难度。提出一种对条带噪声进行检测与去除的方法，首先利用局部梯度对条带噪声的位置进行探测。然后在基于最大后验概率的框架下结合噪声模型与Huber—Markov先验，并通过梯度下降算法进行噪声的去除。使用真实的遥感数据进行了实验，所展示的恢复后数据和对应的频谱图都证明了文中方法的有效性。

Since 1 of the 20 detectors in Terra MODIS band 5 （1.230-1.250 ~m） are noisy, there are sharp and repetitive stripe noise over the entire image. As for MODIS geolocated data, the stripe noise are irregular and sometimes uncontinuous, it brings a difficult problem to the image retrieving process. A detection method was presented to extract the stripe noise, and a maximum a posteriori （MAP） based algorithm was applied to correct the contaminated pixels. A local gradient based method was used to detect the abnormal pixels. In the MAP method, the likelihood probability density function （PDF） was proposed based on a linear image noise model, and a Huber-Markov model was employed as the prior PDF. The gradient descent optimization method was used to receive the destriped image. The proposed algorithm had been tested using a Terra MODIS band 5 geolocated image. The recovered images demonstrate that the proposed algorithm can remove the irregular stripes effectively. The power spectrum also shows a satisfactory result.