1. Echo Curve Analysis and False Echo Mapping

2. Agenda Echo curve False echo mapping What is Echo Curve Analysis (ECA)
What is the Fuzzy value
How to read the Echo Curve
How to recognize False Echo
False echo mapping
Kinds of False Echo Mapping (FEM)
How FEM affects the threshold level
When and how to use the false echo mapping

3. What is echo curve analysis
Echo curve analysis is a static view of the received signal strength from different distances.
There are 9 different signal transmitted and as so there are also 9 different curves on the chart. It possible to look on all beams or each one of them separately.
On the echo curve the selected echoes marks with small square and a vertical dashed line.
Each echo selected have a “Fuzzy value” of between 0 to 1 depend of the reliability level of echo received.

4. What is echo curve analysis

5. What is the Fuzzy value
The “Fuzzy” is a value between 0 to 1 which represent the reliability of echo received.
The reliability level depend on many parameters which we can adjust on the “Advanced Parameters” but also depend on the strength of the echo received and the Threshold level at that echo.
We can change the Fuzzy value by change parameters like “Material slope”, Restrain Coefficient and changing the threshold level by using false echo mapping.

6. How to read the echo curve
On the “All Beams” tab it’s very difficult to understand the reason for selecting/unselecting a specific echo so we analyze it beam by beam.
On a specific beam we can se the Echo (received signal) in blue, the FEM in red and pink (AFEM – red , UFEM – pink) and the threshold which is set by the FEM and the signal strength at the echo’s area.
When the threshold follow the FEM there is a margin between the FEM and the threshold.

7. How to read the echo curve

8. How to recognize false echo
False Echo can be recognize by comparing the Echo Curve Analysis to Manual measurement (hand dipping on a laser device) or by comparing to the reading trend and previous Echo Curve Analysis.
When there is a fuzzy which is far from the cluster of points selected it probably a false echo.
When analyzing curves through time the cluster of points should move according to the material level while false echo will be static and at specific beams.

9. Kinds of false echo mapping
There are 2 kinds of FEM, the Auto False Echo Mapping (AFEM) and the User False Echo Mapping (UFEM). Each one of them cm be disabled at the “Advanced Parameters”. The AFEM can’t be adjust but only reset or disabled.
UFEM can be reset or disabled but also adjust in two ways:
Manual Scan – adjust the UFEM in a specific distance range with a fix threshold value. The user should set the range and the threshold level.
Scan – the scanner copy the current Echo Curve Analysis shape at a specific range which the user set and set the UFEM according to that shape.

10. How FEM affects the threshold level
Threshold is set by three parameter:
AFEM - the threshold will be a bit higher than the AFEM.
UFEM - the threshold will be a bit higher than the UFEM.
The signal strength at the echo’s area, as much as the signal is stronger the threshold is higher.
The final threshold on the Echo Curve Analysis is the higher of the three and any point.
We can set lower threshold only if it is follows the FEM shape by adjusting the UFEM or reset/disable the AFEM .

11. When and how to use the FEM
When the echo is very “noisy” (not while filling) we will consider uploading the threshold level.
If we recognized a false echo we will map it out in one of the two UFEM we have.
If the false echo is at a very specific level we can use the “Scan” option.
If the false echoes are spread we can use eth “Manual Scan”.
When the AFEM interrupt selecting the real material echo we will consider resetting the AFEM of disable it.

12. Thank-you
Questions?