I am doing my project about inspection of austenitic stainless steel welds. in this method there are two method for improving SNR. at the first, optimising of parameters such as mode of beam, frequency and the angel of incidence. secondly,we can apply signal processing to achived signals and then enhancement of SNR. i searched on internet and found only one paper about this. i want to know who are doing this method on anisotropic material such as austenitic steel. in fact i'd like to get more informaton about applying TOFD on this type of material. i have read some standards related to TOFD but non of them not to point to anisotropic structure. althogh at one paper i read about the use of shear wave on anisotropic without any reason and . i dont know whay .most of papers discussed in thick wall howevwr i am doing on thickness near 6 mm.