Range Gate Boundary Three-Row Scan - Biophysical Ultrasound: Echo Timing and Acoustic Interfaces Step by Step

The same echo depth can pass or fail different accepted intervals. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Gate row 1 has accepted bit 1

The echo depth stays 12. Gate low 0 and high 20 give accepted bit 1.

0\le12\le20\quad b=1

Gate row 2 has accepted bit 1

The echo depth stays 12. Gate low 10 and high 14 give accepted bit 1.

10\le12\le14\quad b=1

Gate row 3 has accepted bit 0

The echo depth stays 12. Gate low 13 and high 20 give accepted bit 0.

13\le12\le20\quad b=0

The same echo can pass or fail different gates

The path and depth do not change. Only the accepted interval changes, so the third row rejects the same twelve-meter depth.

\begin{array}{c|c|c|c}d&g_{\min}&g_{\max}&b\\12&0&20&1\\12&10&14&1\\12&13&20&0\\\end{array}