xdc dynamic focus
Purpose: Procedure for using dynamic focusing for an aperture.
Calling: xdc dynamic focus (Th, time, dir zx, dir zy);
Input: Th Pointer to the transducer aperture.
time Time after which the dynamic focus is valid.
dir zx Direction (angle) in radians for the dynamic focus. The direction is taken from the
center for the focus of the transducer in the z-x plane.
dir zy Direction (angle) in radians for the dynamic focus. The direction is taken from the
center for the focus of the transducer in the z-y plane.
Output: none.
1、xdc center focus
xdc_center_focus就是用来确定聚焦的点，这个点是在计算聚焦延时时间的一个参考点，也是动态聚焦的起始点。
Purpose: Procedure for setting the center point for the focusing. This point is used as a reference for calculating
the focusing delay times and as a starting point for dynamic focusing.
Calling: xdc center focus (Th, point);
Input: Th Pointer to the transducer aperture.
point Focus center point.
Output: none
2、xdc focus
purpose：创建孔径的聚焦时间线
input：传感器孔径指针；相关联的焦点valid的时间；聚焦点坐标
Purpose: Procedure for creating a focus time line for an aperture
Calling: xdc focus (Th, times, points);
Input: Th Pointer to the transducer aperture.
times Time after which the associated focus is valid.
points Focus points. Vector with three columns (x,y,z) and one row for each field point.
Output: none.
3、xdc linear array
Purpose: Procedure for creating a linear array aperture.创建线性阵列孔径
Calling: Th = xdc linear array (no elements, width, height, kerf, no sub x, no sub y, focus);
Input: no elements Number of physical elements.
width Width in x-direction of elements.
height Width in y-direction of elements.
kerf Distance in x-direction between elements.
no sub x Number of sub-divisions in x-direction of elements.
no sub y Number of sub-divisions in y-direction of elements.
focus[] Fixed focus for array (x,y,z). Vector with three elements.固定聚焦点
Output: Th A pointer to this transducer aperture.
Example of transducer definition:
Create a 16 elements linear array, and divide the physical elements into 2 by 3 mathematical elements to increase the
accuracy of the simulation.
% Set initial parameters
height=5/1000; % Height of element [m]
width=1/1000; % Width of element [m]
kerf=width/4; % Distance between transducer elements [m]
N_elements=16; % Number of elements
focus=[0 0 40]/1000; % Initial electronic focus
% Define the transducer
Th = xdc_linear_array (N_elements, width, height, kerf, 2, 3, focus);