Flax S W, O'Donnell M
General Electric Med. Syst., Milwaukee, WI.
IEEE Trans Ultrason Ferroelectr Freq Control. 1988;35(6):758-67. doi: 10.1109/58.9333.
Methods for correction of phase aberrations induced by near-field variations in the index of refraction are explored. Using signals obtained from a sampled aperture (i.e. transducer array), phase aberrations can be accurately measured with a correlation approach similar to methods used in adaptive optics and radar. However, the method presented here has no need for a beacon or an ideal point reflector to act as a source for estimating phase errors. It uses signals from random collections of scatterers to determine phase aberrations accurately. Because there is no longer a need for a beacon signal, the method is directly applicable not only to medical ultrasound imaging but also to any coherent imaging system with a sampled aperture, such as radar and sonar.
探索了校正由折射率近场变化引起的相位畸变的方法。利用从采样孔径（即换能器阵列）获得的信号，可以采用类似于自适应光学和雷达中使用的相关方法来精确测量相位畸变。然而，这里提出的方法不需要信标或理想点反射器作为估计相位误差的源。它使用来自散射体随机集合的信号来精确确定相位畸变。由于不再需要信标信号，该方法不仅直接适用于医学超声成像，也适用于任何具有采样孔径的相干成像系统，如雷达和声纳。
