Research On Image Reconstruction Algorithm Based On Acoustic Impedance Rate Line Integral

Ultrasonic technology is a kind of maturely modern technology; it is used in industrial radiography, automotive collision avoidance and medical assay widely, while the main domain of the application of ultrasonic technology is ultrasonic detection. During the period of construction and detection ship, ultrasonic detection has become the important way to guarantee the quality of ship and the equipment working safely.At present, we can get high vertical resolution easily, but if we want to get high lateral resolution, we should make ultrasonic beam very thin that will cost too much, which can't be realized easily. In order to improve the situation, the paper put forward a new method by use of the way of synthesis of multi-channel echo. The method is independent of the location of the flaw and ultrasonic beam, while it s determined by the echo sequences of probes. Using this method, we can detect using wide beam and achieve higher resolution. That will cut cost. We cut the flaw section into N row and N column and then get the clear image of flaw.According to the characteristics of ultrasonic, the ultrasonic emitting by probes diffuses taking probes for center. When the diffusing ultrasonic meets the flaw, it reflects and the probes receive the reflecting ultrasonic. On the basis of the model of echo theory, reconstructs 2D image using echo sequences. We use for reference on the theory of seismic exploration and divide the process of gaining flaw image in to two parts including forward and inversion. During the period of forward, we can get echo sequences file; during the period of inversion, we get the 2D inversion image on basis of echo sequences and the image reconstruction algorithm according to the rate of acoustic impedance.The subject accomplishes scanning the ship weld defects by use of ultrasonic transducer and gain echo sequences files. On the basis of the synthesis of multi-channel echo algorithm, we construct 2D flaw image. In order to implement the algorithm, we make use of IDE Visual Studio 2005 and C#. After analysis on the result of inversion, we find out that we'll get the different 2D defect image which has different resolution and we gain them by using of different echo sequences received by different count of probes. So we know that, we'll get higher resolution by using of more probes in a limited range.