Which transducer type is stated to have the same line density for near and far field?

Which transducer type is stated to have the same line density for near and far field?

• A. Linear array
• B. Phased array
• C. Curved array
• D. Annular array

Answer: (A)

Line density is the spacing of scan lines across the image width, which determines how many lines cover the area you’re imaging. You want a consistent line density so lateral resolution stays uniform from near objects to those farther away. A linear array has evenly spaced elements and scans by sweeping across the width with a straight, flat aperture. This setup yields uniform line spacing that doesn’t change with depth, so the line density remains the same in near and far fields. In contrast, curved, annular, or phased configurations rely on changing the aperture shape or focusing as depth changes, which can alter how many lines occupy a given width at different depths, leading to variable line density.

Line density is the spacing of scan lines across the image width, which determines how many lines cover the area you’re imaging. You want a consistent line density so lateral resolution stays uniform from near objects to those farther away.

A linear array has evenly spaced elements and scans by sweeping across the width with a straight, flat aperture. This setup yields uniform line spacing that doesn’t change with depth, so the line density remains the same in near and far fields. In contrast, curved, annular, or phased configurations rely on changing the aperture shape or focusing as depth changes, which can alter how many lines occupy a given width at different depths, leading to variable line density.