摘要
为解决广义相干系数用于合成孔径成像中所存在的运算量大,图像对比度改善有限等问题,提出空间广义相干系数加权成像方法。该算法根据单个孔径成像结果之间的相干性来计算相干系数,通过加权空间合成进行成像。采用对FieldⅡ仿真点目标和吸声斑目标的数据进行成像表明,算法不仅使运算量减少N(N为阵元数)倍,而且相对于传统的广义相干系数算法,算法对散射点成像可提高信噪比7 dB,对于吸声斑成像可提高对比度3.2 dB。可见算法可以有效地提高成像速度和成像质量。
General coherence factor weighted algorithm has been introduced to synthetic aperture imaging to increase the contrast, but its calculated amount is huge and the contrast can be improved limited. A method named space general coherence factor weighted algorithm was proposed, in which, the coherence factor is calculated according to the coherence among images constructed with single element transmissions, and then the resultant factor is used to weight the images to get final image by space synthesis. Simulations to points object and speckle object pattern using field II show that the calculated amount of the method is reduced to 1/N （N is element numbers of the array traducer）, and compared with general coherence factor weighted algorithm, the SNR of the image to point object is increased by 7 dB. The contrast of the image to sound-absorbing speckle is increased by 3.5 dB. The method can increase the speed of imaging and improve the image quality.
出处
《声学学报》
EI
CSCD
北大核心
2012年第6期637-641,共5页
Acta Acustica
基金
国家自然科学基金(60871087
61 172037)
2010年合肥工业大学博士专项基金(2010HGBZ0615)资助
