How the echoview detect schools (School detection)

Fig. 1 Image of an echo remaining after a certain threshold settings.

After the threshold settings is done and a certain edge of the echo is determined (Fig.1), Echoview conducts “School detection” by the following three settings.

1. Minimum candidate length / height
2. Maximum vertical / horizontal linking distance
3. Minimum total school length / height

First on setting 1., Echoview determines the minimum size of an echo as a candidate of school.
At the example on Fig.1, if you set the minimum candidate length / height to the size bigger than the blue echo ( ●), ● is excluded from detection.

Next on setting 2., echoview determines the distance that we decide the neighboring school as single school.
For example, if echo A and C is closer than the 2. distance, A and C is defined as a single school (The distance between C and B is far than 2., so there are recognized as a independent school).

Echoview finally detects school out of the rest candidate echoes by size of setting 3. For example, if we decide the minimum total school length / height as the red arrow in Fig.1, candidate B is excluded. So finally, candidates bigger than Setting 3.; D and the combined image of A and C becomes the school detected.